Update July 15 2015: I see lots of people coming to this post. This is the latest word from ZTE: ZTE Zmax: Android 5.x? Ermmmm
From XDA Developers:
There is a Lollipop update coming for the ZTE Z max soon a least that is what one the reps told me he said they are working on some bug fixes and stuff but as so as there are done they will release it!!!!
And someone else at XDA Developers replies:
I honestly done know why everyone seems to be pooping themselves over the new lollipop update. I work in a testing environment and from my experience lollipop has more compatibility issues, battery draining, and laggy loads than kitkat. It feels like a bloated mess in comparison. =/
Meanwhile, they’re still trying to snatch root out of the greedy paws of ZTE/T-Mobile.
If they were to gain root — and ZTE were to also unlock the damn bootloader — it’d be no contest. The ZTE Zmax would win over the Sony Xperia T2 Ultra. It has 2GBs of RAM and 16GBs of internal storage versus 1GB and 8GBs for the T2 Ultra.