Overall I've got the following impression of this firmware:

1. Switching from 3G -> 4G is more reliable than on any MIUI rom. First of all I don't loose internet connectivity during the switch (with MIUI I always do) and secondly it founds 4G networks almost instantly, and for MIUI it took minutes.

2. I've tried to flash open gapps stock - it basically made them unusable (was unable to create account), but open gapps mini worked ok for me. Though got a problem with black home screen and very slow phone until I've changed home launcher back to trebuschet.

3. Battery usage also increased in my use cases. I usually got 25% battery/8h, but now it's more like 35%/8h. Though it may be related to the fact that all messangers, etc syncs as often as they want, and with MIUI I never was able to properly receive all push notifications, etc for most of the apps.

4. According to some benchmarks, it seems that this rom is a tiny bit faster. (geekbench results increased by 7% for example). Though that doesn't really matter for me.

5. I usually have more RAM available and apps killed less aggressively.