The most interesting thing about Huawei's latest flagship, the Mate 9, is actually invisible to the naked eye. Under the hood, the phone uses machine learning to anticipate which apps you're going to use when, allowing for supposedly smoother performance. What the phone would have been like without this AI, we don't know, but we can say that the performance feels brisk throughout. If fluid day-to-day use seems like table stakes, you might also be impressed with the long battery life, bright display and the fact that it actually has a headphone jack. Unfortunately, what's otherwise a great phone stumbles with low-light photography, as well as some heavy-handed software tweaks that will turn off Android purists.