I'm on XA2, and I have some problems. I use the XA2 as my daily driver, and regret the upgrade at this moment. I am not in the EA programme.

- AlienDalvikControl had an invalid uninstall script at some point of time, and as a result I had two versions installed.
- The upgrade process said there were problems, and the upgrade would not follow through (or something similar). Well, the upgrade was here to stay, and I had a black screen. SSH was available, and with some help I uninstalled AlienDalvikControl. Then things seemed OK.
- OKBoard made the screen black above the keyboard. After disabling more things seemed OK.
- Except Email did not update, nor fruux (CalDAV, CardDAV). A proven solution is to delete the account, and create it again. Unfortunately I cannot create new Email accounts: the busy indicator never stops. I haven't got any response so far to resolve this.

So phone, bluetooth, browser, Whatsapp all work. But no Email, which is very unpractical.
(I added a new fruux account just now, hurray!)

For XA2 you need 700 MB of free space in root.