Lots of software issues
I bought a Umi Z back in January. I cannot be more disappointed with it. Since I've owned it I have had many software issues such as Google Music not working, screen not rotating, data connection dropping, etc. A month ago or so Umi finally released the update to Android 7 (several months late though). Again, lots of software issues. If you are a Umi owner then you are going to live hoping that Umi will release a fix soon.