Xiaomi Mi A2 review: Is this the Android One phone to get?

Overview

It's a fair bet that the first time Xiaomi released a phone not running MIUI, there was cheering in the streets. Well, maybe just the streets of South Asia, South America, and emerging Western markets like Russia, at any rate. But that's still a lot of streets. 

Why? For some background, let's hark back to 2014 when Google first revealed Android One, a range of devices that would run virtually stock Android. In an Android world seemingly overran by bloatware-packed devices, and with Google's Nexus and Pixel phones still strictly limited to certain developed markets, Android One phones are music to the ears of pure Android fans. Google would handle the system and security updates; the manufacturers partnering with them only had to build the hardware (and were free to incorporate their own specialized camera and other apps.)

The problem, however, was in the execution of this grand idea. The first and second waves of Android One devices were strictly localized, coming from brands such as Micromax of India, Nexian of Indonesia, and Infinix of Nigeria, and the hardware specs were decidedly low-end: MediaTek MT6582 1.3GHz quad-core processors and 2GB of RAM were par for the course. In 2016, Japanese telco SoftBank tried a Sharp model, but even though it was at the time the most prestigious brand under the Android One umbrella, it was strictly a Japan-only release. There was nothing even remotely close to Nexus or Pixel material, and it seemed like the closest thing to a stock Android dream for most people would still have to be the OnePlus 3 series.

But in September 2017 Xiaomi, that validated value veteran, unexpectedly burst onto the scene with a phone widely viewed by many as the "budget Pixel": the Mi A1. Driven by a reasonably modern octa-core Qualcomm Snapdragon 625, the A1 was equipped with dual 12-megapixel cameras, and even boasted something not found on any Pixel - a microSD card slot! Better yet, Xiaomi's marketing might and reach meant that it was eventually rolled out in 48 markets, from Singapore to Slovakia.

So, a year later, here we are with the Mi A2. Given that the A1 firmly established itself as a cheap and cheerful champ in the best Xiaomi traditions, the Snapdragon 660 and 20-megapixel mentions in the A2's spec list would seem to suggest yet another value mammoth this time round. Is that so? Let's dive into the belly of the beast and find out!

Design

No one would ever use terms like "stand-out" or "groundbreaking" when describing the exterior of a budget Xiaomi (or Redmi) device. By recycling the basic designs of its phones, the Chinese juggernaut saves its dough for where it counts: performance and features.

Don't expect anything new, then, with the Mi A2. This device, like the endless ranks of Redmi-Pro-Plus-Notes before it, is still built from a glass-aluminum sandwich. Last year's special color, rose red, has vanished in favor of a light blue, but otherwise you still get the same champagne gold and boring black options as with every other phone on the planet.

The list of exterior fitments is not much to shout about. The 5.99-inch 18:9 LTPS IPS LCD, shared with the Redmi 5 Plus and Note 5 phones, has improved marginally over the Mi A1 in color accuracy and contrast ratio, but is still too dim for outdoor use. Don't expect stereo speakers, either.

Round the back, the dual cameras are placed at the top left, with the LED flash smack in the middle of the two lenses. Not only that, the camera forms a hump; along with the offset position, this means the phone won't lie flat on a table.

Thankfully, there's an IR blaster and dual-SIM slots. But there's no expandable memory: the 64GB of storage you get is fixed, and you can't use one of the SIM slots as a memory card slot.

There's no 3.5mm headphone jack, too. We could see the reason behind its removal on the flagship Mi 8 - but why on this phone? Xiaomi does bundle an adaptor in the Mi A2's box, but it's cold comfort. The phone also uses USB-C for charging and data transfer.

Software

Not much needs to be said about the Oreo-based goodness of Android One on the Mi A2. Stock Android and all the beauty that it brings - such as properly-working "OK Google" functionality even with the screen off - were the recipe for the Mi A1's success, and so it should be with the Mi A2.

There are just a few Xiaomi apps, too, such as a Feedback app, a file manager, a Mi Remote app for controlling that IR blaster, and a Mi Drop file-transfer app. But the most important Xiaomi app is the camera app, which is also the only Xiaomi app that can't (and shouldn't) be uninstalled.

However, do remember that being Android One-based doesn't necessarily mean a phone is updated at the same speed or schedule as Google's own (Pixel) phones. We've seen several such devices, like the Nokia 7 Plus, that are pretty slow to receive updates. Also, the performance of certain hardware components may be affected by the drivers or apps they provide, and for those you'd have to trust the manufacturer for solutions. Caveat emptor!

Another observation: face unlock doesn't work - and hasn't worked - in the Mi A2 or any of the Android One phones we've tried to date, for some inexplicable reason. Under the Smart Lock setting in these phones, there's always the option to add a "Trusted face",  but the phone doesn't even attempt to scan it when the power key is pressed.

Performance

With a Qualcomm Snapdragon 625 providing the tractive force, the Mi A1 proved to be a solid, if uninspiring, performer.

This time around, Xiaomi has gone for the jugular and plumbed in a Snapdragon 660, which is as different from the 625 as day from night, for it employs Qualcomm's custom optimized Kryo cores instead of stock ARM Cortex A-series cores, for which Qualcomm claims a 30% performance improvement. The 660 also features the latest Adreno 512 GPU, which is clocked at 800MHz against the Adreno 506's 650MHz on the Snapdragon 625.

All this means that the Mi A2 feels and behaves almost like a first-generation Pixel. Apps open with delays that are no longer irritating, and there is a marked decrease in the amount of micro-stuttering when browsing the web. The benchmarks back up these anecdotal observations, too.

For our comparison, we've put together a motley crew of devices that either share the Mi A2's performance or price point: the Snapdragon 660-equipped vivo X21 which costs about S$200 more, Xiaomi's own Redmi 5 Plus, and of course, the original Mi A1.

SunSpider

Let's start with SunSpider, which measures JavaScript processing performance. SunSpider takes into consideration not just the underlying hardware performance, but how optimized a particular platform is in delivering a high-speed web browsing experience.

The gap is not actually huge between the 660 devices and the 625 ones:

3DMark

3DMark Sling Shot Unlimited 3.0 uses a mix of graphics and physics tests to measure hardware 3D performance.

Basemark

BaseMark OS measures overall system performance over a number of different metrics. And with a stock Android build, the Mi A2 is once again caught napping by nobod...  wait, the vivo X21? Given that this is a budget device, perhaps slow RAM is to blame.

Mi A2's biggest problem: Battery life

The original A1's Snapdragon 625 processor is based on Cortex-A53 cores, which, while no ball of fire, were admittedly parsimonious enough to support a full day of moderate use. With a faster Snapdragon 660 and a bigger 6-inch screen, Xiaomi has instead chosen to cram a slightly smaller battery (3,010mAh) in the A2.

On our standard battery test where we've to:

• Loop a 720-pixel video with screen brightness and volume at 100%,
• Keep the Wi-Fi and Bluetooth radios turned on, and
• Make sure the phone is constantly streaming data through email and Twitter...

...the Mi A2 turned in a battery life figure of just under 6 hours.

To obtain more real-world use statistics, we fired up GSam Battery Monitor to test the device in an even more media-focused usage scenario. Our suspicions were further confirmed: over about a half-hour period of which about 70% was YouTube, some photography, and web browsing, power consumption ran as high as 10% per hour.

In day-to-day use, we were able to eke out a little more than 12 hours - which meant that unplugging the phone at 7am would see it entering battery saver mode at about 6pm. Over the weekends, when we had more free time on our hands, this easily happened around 3pm. This writer will go out on a limb and say that he hasn't seen such poor battery life from a recent-model smartphone.

To make matters worse, there's no USB Power Delivery or Quick Charge fast charging support on the Mi A2.

Camera Performance

While the Mi A1 employed a ho-hum pair of rear 12-megapixel cameras, Xiaomi has now kitted out the Mi A2 with a setup that, on paper, puts its flagship Mi 8 to shame.

These dual rear cameras have 12 and 20-megapixel resolutions, and the latter is based on a Sony IMX376 sensor that employs a feature Sony calls "Super Pixel", a form of pixel binning. Simply out, it "joins" 4 adjacent pixels into a single "large pixel" to improve sensitivity in low light.

In good light, the Mi A2 turns in a solid performance, with nice (if warm) colors, good detail, and excellent dynamic range.

Xiaomi's camera app is installed on the Mi A2, and it enables way more features than Pixel's stock Google Camera app, such as long exposure up to 30 seconds. The shot below was taken at 4 seconds and ISO 100. (For GCam fans, we didn't manage to get any hacked build to work at the time.)

In scenes with mixed lighting, such as this one where the sky was cold and dreary, the Mi A2 did well at not messing up the white balance. (But if you look closely, there's an HDR (image blending) artifact in the lower left corner.)

The Mi A2, like other Xiaomi phones, also generally does well in depth-effect mode, with decent edge masking and pleasing blurring of the correct objects.

The front camera is a single 20-megapixel sensor, also using the Sony IMX376 and also employing pixel binning. We've no complaints about its image quality.

This writer also had a Samsung Galaxy A8 Star handy at the time, and the A8 Star is a very similar phone under the hood: it's also powered by the Snapdragon 660 power and employs a very similar 24 + 16-megapixel setup where the 24MP sensor uses pixel binning.

Here's a quick comparison of the two phones' performance under low light:

The photo from the Samsung A8 Star is obviously artificially sharpened, and lacks structure (textural detail). It appears that the 24-megapixel sensor produces a low-resolution binned image, which is then upscaled to the original resolution.

On the other hand, the Mi A2's image is far more consistent in its detail, and has more pleasing shadow tones. Xiaomi's noise-reduction algorithm is also less heavy-handed - there is still noise in the sky - but the picturesque glow is a winner!

The A8 Star also has this tendency to produce a pink cast in low-light shots, and a paradoxical increase in contrast in scenes with very low light levels - evidence of heavy noise-reduction techniques. On the other hand, the Mi A2 is more consistent in producing contrasty and warm shots.



Overall, both phones do a great job in good light, but the Mi A2 shows its chops when the lights go down. Also, given that neither phone has OIS, we had less trouble with blurred shots on the Mi A2.

Conclusion

Take a great camera, a fast processor, and stock Android at face value, and it's really easy to like the Xiaomi Mi A2 - if you pay no heed to the quickly-dropping battery icon. While 12 or so hours of runtime is not wholly impractical if you're deskbound or if your phone stays in a locker while you work, it does severely limit the A2's appeal for students or sales executives, who are constantly on social media and texting their thumbs off or replying to emails. The 3,010mAh cell is not likely to survive a whole day's worth of class chalet or company off-site work-plan seminar - unless you have a power bank around.

Again, it's really a shame, because the Mi A2 has what it takes for us to call it the leader of the Android One value pack, since it does possess a very competent processor and a solid camera. But this leadership still rings hollow, since the Android One competition is still very thin on the ground, and there are many competitors in the same price bracket. And as we've pointed out, Android One - unlike owning an actual Pixel device - is not a guarantee of immediate updates.

If stock Android is not a must-have, many alternatives are worth considering. The Redmi Note 5 Pro/5 Plus have slower processors and slightly inferior cameras, but larger batteries and lower price tags. Huawei's S$398 Nova 3i gives you a 3,300mAh battery and 128GB of expandable storage, plus dual cameras on the back and front. Or how about Xiaomi's own Pocophone F1, which nets you the chart-topping Snapdragon 845 processor and a 4,000mAh battery at only S$449!

The Xiaomi Mi A2 (4GB RAM / 64GB storage) is priced at S$369, and is now available through retailers such as Lazada.