Yes, I got one specifically for playing with UE and it works quite well.
The sample projects (Mobile Temple, Strategy Game etc.) all work fine. Mobile Temple is a bit slow, but is expected to get better with a driver update (see this).
However the current state of UE4 on Android can be somewhat disappointing - as far as I understand there is no support for any sort of dynamic lighting, that is you can’t have moving lights, you can’t have real-time shadows, and even static lights use some sort of pre-calculated light volume to light moving objects, at least that is what I think they do, I couldn’t make lighting work on moving objects at all (this is what it looks like)… it’s not obvious how it is supposed to work, neither it is properly documented.
So keep that it mind to avoid disappointment if you’re only buying it for UE!