I made it up to 7.8 and everything seemed fine.
Going to 7.9 gave me an email issue where none of my emails would send. I was receiving them fine, but anything I composed would just stay in a "sending" status.
Did a wipe and went back to a previous backup. Same thing.
Had to go all the way back to nandroid copy I had right after rooting (email worked) and then reloaded a nandroid of 7.4. Back to 7.6 with no problems now, and I think that is where I am staying for a while.