Usage Notes, Battery Life, and Conclusion
I would love to cover cellular performance in-depth in phone reviews, and perhaps that can be added to future reviews. Currently I use T-Mobile, and at least have access to a fairly robust LTE network where I live. To this end my use of the Mate 9 over a two-month span was actually uneventful; essentially matching the results I had with an iPhone 7 during the same span. One area that was different was call quality, however, as the Mate 9 does not support VoLTE, and I was not able to benefit from what T-Mobile markets as "HD Voice" as I would on other handsets such as the iPhone 7 (though, for what it's worth, no phone has matched the voice quality of my old Nexus 6 on T-Mobile to this point).
Network performance aside, the biggest part of the experience with any phone ends up being with the OS and its user interface (UI). This is the part we interact with constantly, and with the Mate 9 we are just a little closer to a great experience. The phone runs Android 7.0, and Huawei is up to version 5.0 of their EMUI with the Mate 9. Other than a some app management alerts (yes, I know my podcast app is consuming power in the background!), which can be managed, I found it very usable. I will point out that after switching to the home screen style called “drawer” in settings, the interface gets very close to stock Android (other than the custom settings arrangement), and in general Nougat seems to have limited the extent of the Huawei-branded extras I found rather annoying with the Mate 8.
Upper row, left is default view; upper row, right is 'drawer' view
Split-screen functionality works very well (visible on the bottom right of the above UI screenshot collage), and while built-in apps are generally not my preference outside of a Nexus/Pixel device, the basics such as the stock camera and messaging apps are fine. I download all of the stock Google apps for any phone I use (even on iOS), so my phone experience is pretty similar across phones and platforms – but that is obviously up to the individual.
I will briefly touch on audio, as the Mate 9 (in addition to including a 3.5mm headphone jack, thank you very much!) implements a front-facing stereo speaker system for the first time. The Mate 8 offered excellent loudspeaker quality, with very good clarity and plenty of volume, and the Mate 9 is similar – though the second "stereo" speaker is simply the earpiece driver, which produces no bass or lower midrange to speak of. The effect is almost that of having a dedicated tweeter, which does make the sound seem more detailed, but true stereo is lost.
The Mate 9 is equipped with a 4000 mAh Li-po (lithium polymer) battery, and this is identical to the battery from the Mate 8. When I originally tested that phone I was not able to provide a comparison to other handsets using our standard PCPer battery test; instead using data from PCMark's Work battery life test. To provide an apples-to-apples look at battery life vs the Mate 8 the Mate 8 has been newly tested, and results are included along with the Mate 9 below.
I will be adding additional battery tests to future reviews, but the three results here at least provide a bit of perspective on the battery life of the Mate 9. Both Mate phones are very strong in this department, with the Mate 8 a particular standout. I knew that both the Mate 8 and Mate 9 offered great real-life results, with my own use allowing me to go up to a day and a half before charging the phone; but these results (at 180 lux screen brightness, constant browsing over Wi-Fi) are fantastic. The Mate 8 might be the champion, but the Mate 9's performance (with a more powerful SoC) is still very impressive.
The iPhone 7, on the other hand, is not a strong performer with constant use. When I first ran this test on my brand new, launch-day iPhone 7 (tested that very day), I was convinced something had gone wrong. Now, 5 months down the road (my wife used the phone every day during this time) the run time is even lower, and the 7 Plus did not fare any better for me. I am now convinced that iPhone 7 is just a poor performer with battery life, and it turns out that achieving higher clocks on the same process node results in less battery efficiency for Apple in constant use (as I understand it their low-power cores in the A10 Fusion are not in use for benchmarks, forcing the high-performance cores to remain active). If you are a heavier phone user like me, you will notice a significant advantage with a phone like the Mate 9 compared to an iPhone 7.
In most respects the Mate 9 is a true upgrade from the previous model. It offers a new SoC that boasts significantly improved graphics power, refined industrial design that makes the phone look and feel every bit as premium as a Samsung or Apple handset, and a much improved camera. It is not perfect, but it makes a compelling premium option at its $600 MSRP when compared to an iPhone 7 ($650) or Galaxy S7 (~$670). I find it very easy to recommend based on overall camera quality (especially B&W!), excellent battery life, and a very good display. Drawbacks are rather minor, and include lack of VoLTE support, and (to a lesser extent) the stereo loudspeaker design; but no current phone is “perfect”, now is it?