Mobile Buying Guide: How To Purchase The Right Mobile (Part II)

Which phone should I buy?" This is the single most common question readers like you ask phone reviewers like us every day. We get it -- it can be a challenge, especially with superb choices such as the Samsung Galaxy S6 and iPhone 6S . But depending on your price range and what's available where you live, the new phone you should be getting may not be a flagship -- it could turn out to be the Nokia Lumia 640.

On the bright side, options are a good thing, so long as you're armed with the knowledge necessary to make smart shopping decisions. Sit tight as we lay out what you need to know to find the best new device for you.

Three key phone-shopping essentials

1. Don't be a cheapskate

Contract or no contract, chances are high that once you commit to a new phone, you'll hang onto it for a while. Therefore, buy the best device you can afford. You'll need the camera quality and processor to last you as long as possible until your next upgrade. The battery, too, becomes less efficient at holding a charge as your phone ages, so you'll want to choose one with a high capacity.

An added benefit of going for a high-end handset, say like an iPhone 6S or LG V10, is that the resale value tends to hold over time, so make your device an investment that pays off.

2. Know which phone features you want

If you understand exactly which features and capabilities you'd like to see in your new phone, it'll help you avoid paying too much for those you don't want or need. Some, like the Samsung Galaxy S6 Edge+, have it all -- including a large, curved screen with its own user interface controls. Yet if you'll never use the new UI, you'll be overspending for a pricey novelty device.

3. Find the right design

Buying a cell phone means entering into a deeply personal relationship with a highly portable physical object. That's why you should think hard about how it's designed, since you and it will be spending plenty of quality time together. Make sure you're comfortable with the way it looks and -- this is important -- feels in your hand, and make sure that your phone-to-be reflects your personal sense of style. This is as true for sleek metal handsets and simple flip phones as it is for rubber-plated rugged handsets.

A thick, rugged handset like the Kyocera DuraXV won't do you any good if you don't enjoy toting it around.

Cell phone types

Smartphones

At the top of today's handset pecking order is the smartphone. These devices typically have the most power, and top-notch components: the fastest processors and Wi-Fi; the highest image resolution and memory capacity and the most pixel-rich screens. By definition, they run true mobile operating systems; think Apple iOS and Google Android, but also Microsoft Windows 10 Mobile and (to a much lesser extent) BlackBerry 10. They also support downloadable applications through virtual storefronts that are tied to their associated software platforms, like the Google Play store. Because of all their capabilities, smartphones are usually the most expensive phones on the market.

Messaging or feature phones

One step below smartphones, feature phones strive to offer many of the same capabilities as smartphones. Instead of popular mobile operating systems, these gadgets run proprietary software crafted by their manufacturers, such as Samsung, LG or Kyocera. Many feature phones are made primarily for text messaging and email, though you won't be required to buy a data plan. Several of these designs sport full QWERTY physical keyboards. With a raft of cheap, available Android and Windows devices, feature handsets are fewer and farther between.

Basic phones

There are plenty of people who have no interest in viewing full desktop-quality Web pages or running apps on a mobile device. Simply put, they just want a new phone for making calls, and that's it. No funny stuff. Basic handsets are uncomplicated and use traditional simple keypads. They typically come in clamshell designs that flip open, or in tall, narrow candy bar form. They're usually lighter and smaller than feature phones and smartphones.

The BlackBerry Priv is a rare modern device to have both a classic (slide-out) QWERTY keyboard and a smartphone OS.

Key consideration points

Screen size

Large screens (5.5 inches or greater)

Smartphones are getting bigger; that part is undeniable. A 5-inch screen (measured diagonally) used to be considered massive, but on today's sliding scale, that's about the middle of the pack. Even Apple has gotten into the "phablet" game with the 5.5-inch iPhone 6 Plus. A 6.8-inch device is the largest we've seen (on the Huawei P8 Max), but most people consider the 6-inch Google Nexus 6 and Nokia Lumia 1320 to be about as large as they'd really want to palm. You can find both budget and high-end handsets at the top of the sizing scale, like the 5.7-inch LG G Vista and Samsung Galaxy Note 5, respectively.

Medium screens (5.0-5.4 inches)

Phones in this middle category range from mid-tier to the most premium. They tend to measure exactly 5 inches or just a skosh larger, like Samsung's Galaxy S6 family at 5.1, or the much more entry-level Motorola Moto G at 5. One benefit: phone owners can grip with one hand while their thumbs comfortably reach all portions of the display.

Small screens (4.5-4.9 inches)

Thanks to the increasing number of gargantuan smartphones hitting store shelves, compact cell phones are a shrinking segment of the mobile handset market. That said, some people still place portability highest on their list of phone features. Unfortunately, options are slim. Most phones in this size category are entry-level smartphones or feature phones with low screen resolutions, like the 4.5-inch Motorola Moto E 4G LTE. But once in a while there are gems, like the Alcatel OneTouch Idol 3, which sports a 4.7-inch display, a sharp 720-pixel resolution, and a 13-megapixel camera.

For more on specific display technologies, check out the "deeper dive" section at the end of this guide.

Processor

The beating heart of any device is its processor, or CPU. It provides the computing power to churn through various tasks, like opening and running applications. A fast processor also has a big impact on overall performance, such as how smoothly a phone handles flipping through menus and running home screens.

Traditionally, clock speed, listed in gigahertz (GHz), has been the quick way to judge CPU power. These days a chip's architecture, specifically how many computing cores it has, is becoming a more reliable predictor. Another factor is that older processors tend to use less efficient designs, making them worse performers while being harder on batteries than their newer counterparts. We talk more about processors below.

Camera

A phone's camera quality depends on a whole host of variables. More megapixels will always sound better on a fact sheet, but we know some good 13-megapixel cameras that take better photos than a bad 20-megapixel shooter. (Read on and see the bottom section for more details.)

Also important are the lens quality, which could aid the sensor by exposing it to more light. The sensor itself might also offer a lower pixel count, but be more sensitive to illumination, resulting in better performance in low-light conditions.

Many phones -- such as those from HTC and Microsoft (formerly Nokia) -- ship with fancy image processors that promise high image quality, plus the horsepower to drive the camera and autofocusing systems faster. The end result is nimble shot-to-shot times with minimal shutter lag.

Apple's iSight camera improves year after year, with optical image stabilization being introduced to the iPhone line with 2014's 6 Plus. And though its megapixel count remained at 8, Apple upped the ante to 12 with the iPhone 6S and 6S Plus.

Optical image stabilization is becoming increasingly important for phones, too. The Galaxy Note 5 and the iPhone 6S Plus are two that include the physical component for steadier, clearer photos.

With the rise of social network sharing, front-facing cameras are more important than ever before. In addition to seeing higher-resolution topside cameras, vendors are also concentrating on more software dedicated to the art of selfies. The Sony Xperia C5 and Motorola Moto X Pure Edition (or X Style as it's known outside the US) even come with a flash.

Battery

If your cell phone battery conks out, all the snazzy features in the world won't be able to help you. Manufacturers have begun to recognize the critical importance of battery life and are squeezing greater-capacity batteries into their phones. Typical phone batteries start in the neighborhood of 1,700mAh and can go all the way up to 4,000mAh, like the Huawei Ascend Mate 7.

Manufacturers list battery performance in terms of talk time, standby time, or how many hours you can expect a device to perform tasks such as playing video and music.

Wireless carriers

Choosing a wireless carrier is a less difficult prospect than it used to be, with more phones sold across carriers and the higher prevalence of contract and contract-free options. Still, it requires a lot of time and math to puzzle out exactly which operator offers you the best deal. It's worth the time.

In the US there are four major carriers that offer devices with and without a contract.

That said, when selecting a carrier, first on your list of criteria should be coverage. You'll want a carrier with decent coverage in your home and at work, and all the places in between. For more about carriers and networks, see the next section.

Figure out if you'll be sticking to urban centers or trekking through rural areas often. Perhaps you won't even leave your home neighborhood much, or conversely, you plan on doing plenty of international trips. With your wireless usage in mind, settle on a carrier that offers broad coverage. Alternatively, you may be satisfied with a regional carrier that covers a limited area.

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Feature deeper dives

Want to know more about some of the features mentioned above? Read on for a deeper analysis.

Mobile networks and 4G data

The wireless network technology at the backbone of your smartphone is a veritable alphabet soup of acronyms and industry buzzwords, and you could spend an eternity studying how cellular infrastructure is built and works. Here's a basic overview of what you need to know.

CDMA

CDMA stands for "code division multiple access," but more importantly, it's a method by which cellular radios transmit and receive voice and data. This standard is found mostly in America and to some extent in Asian countries such as Japan and Korea. For example, major US carriers that use wireless networks based on CDMA are Verizon and Sprint.

GSM

GSM, aka the Global System for Mobile Communications, first referred to in French as Groupe Special Mobile, is a standard created for use in the UK and the rest of Europe. GSM then spread to other corners of the world, with carriers operating GSM networks across Asia, the Middle East and Africa. It's the most widespread of the cellular standards. The two technologies are incompatible, so phones strictly locked to CDMA networks won't work in GSM areas, and vice versa. However, the Moto X Pure Edition is unique in that it's equipped with radios that support either standard, so it's cross-compatible with both CDMA and GSM carriers.

HSPA+

Based on the older High-Speed Packet Access, which topped out at 3G speeds, HSPA+ supports a theoretical peak download throughput of 168Mbps. This may sound pretty fast, but in practice the protocol delivers data speeds just marginally faster than 3G, and average download speeds of approximately 3 to 5Mbps. This causes us to think of it as really a 3.5G wireless solution.

4G and LTE

LTE, or Long Term Evolution, is the current generation of faster data connectivity for both GSM and CDMA technologies. Often referred to as 4G or 4G LTE, it's the speediest data throughput you can get right now. LTE Advanced, a step beyond LTE (but still part of the same family) gives data speeds still another boost, and is rolling out in bits and pieces. VOLTE, which stands for Voice Over LTE, relays voice service over data channels, allowing you to surf and speak at the same time even if you have a CDMA phone.

Wi-Fi Only

Making and receiving calls over local Wi-Fi networks (the same kind that's set up at your home or local cafe) is nothing new. Apps like Skype and WhatsApp offer this functionality, and they're useful when you're in an area with weak or nonexistent cellular coverage. In addition, certain mobile networks already support this service built-in with some of their handsets. But there are a handful of carriers that exclusively employ Wi-Fi networks as the default method to patch calls and enable users to surf the Web. The most high-profile of these services is Google's Project Fi, which is only available in the US for now. Because data usage is minimized, phone bills can be generally cheaper. But users are limited to what devices they can use depending on compatibility.

Screen technologies

LCD

LCD screens, short for liquid crystal display, have come a long way from the alarm clocks and digital wristwatches of the 1980s. Today's smartphone LCD panels offer HD resolutions of up to 2,560x1,440 pixels, with the exception of the Sony Xperia Z5 Premium, which has a 3,840x2,160-pixel resolution (or 4K) display. LCDs use of an external backlight for illumination, which often results in more shallow viewing angles and lower contrast compared with AMOLED displays. On the other hand, colors often appear more natural.

Retina Display

Apple uses what it calls Retina Displays in its latest iPhones. This is essentially a clever marketing phrase to say the iPhones (the iPhone 4 and up) sports LCD screens with minimum resolutions of 326 pixels per inch (ppi).

A reference device running the Snapdragon 820 chip

Apple A9

Apple's latest wafer of processing silicon graces the iPhone 6S and 6S Plus with 64-bit mobile phone processing. Apple claims the system is 70 percent faster than the A8. All other details remain officially hush-hush.

Samsung Exynos

As well as displays and memory components, Samsung makes its own processors under the Exynos brand. Its most recently announced Exynos chip, the Exynos 7 Octa uses 64-bit computing, and has turned up in some of the company's top phones, like the Galaxy S6 and Galaxy Note 5. Other Samsung phones do continue to use Qualcomm's chipsets, however.

Motorola X8

Motorola took a unique approach in its smartphone lineup for 2013. Instead of cramming the fastest off-the-shelf CPUs into its phones, it made a hybrid. 2014's haul returned to Qualcomm and has continued through 2015.

MediaTek

MediaTek is a Qualcomm rival whose chips are typically found in smartphones for Asia and for emerging markets.

This was the end of Part II of our guide to finding the right mobile. You can check out our first part here.