The very nice thing about ASUS Zenfone 2 is that they (currently) update the software, both Android ZenUI OS and built-in applications very rapidly.
I also noticed a few problems though. Sometimes Android System UI crashes (about once in 1-3 days), which is worrying but it resumes successfully, however if I was composing a (long!) text message then it’s wiped away. 🙁
A few Virtual Reality/3D/Cardboard applications are not working as intended (Vrse with blank black video although there is sound) or just crashes (Tokyo VR).
Hopefully sooner than later these issues will be resolved either by ASUS or software developer or Google. Aamiin. 🙂