ASUS made an ambitious promise back in August 2017, around the same time when Android 8.0 was officially being released to the public. All of Asus's ZenFone 4 devices, as well as the ZenFone 3 series, were promised to be updated to Android Oreo. This was a very big promise, because many of the devices in both of these series fell in the low/mid end segment, and some even dated back to 2016. With ZenUI 4.0 onwards, Asus also promised to cut back on the bloatware, bringing down the number of pre-installed applications from 35 to 16.
Asus certainly seems intent on delivering that promise, as the Asus ZenFone 3 Max has now received its Android Oreo 8.1 update. What makes this update impressive is the fact that this device is a low-end device, coming with the Qualcomm Snapdragon 430 SoC, it was launched back in 2016 with Android 6.0 Marshmallow. One could argue that the device should have received at least one version upgrade, but this is, in fact, its second version upgrade. The first being its official Android 7.0 Nougat update.
The update also updates Asus's ZenUI skin to ZenUI 5.0. The official changelog for the update simply mentions the Android OS and ZenUI updates, but in all likeliness, there will also be an Android security update included with this update.
Asus ZenUI 5.0 brings along features like redesigned Settings page, lock screen wallpaper slideshow, Smart Screen On functionality, Suggest Apps (that predicts the app you are likely to use based on contexts and makes them easily accessible), Scheduled Charging, OptiFlex 3.0 for RAM and app optimizations, Game Genie (helping you perform actions like live-streaming and muting alerts), Twin Apps, Face Unlock and more.
This update is rolling out to the Asus ZenFone 3 Max (ZC553KL) and will arrive on the device as an OTA. The update system takes about a week to complete its automatic push, so if you haven't received the update yet, you can manually check for an update.