Boy, was I wrong. Just now I was watching TV via a FiOS One Mini, pressed Guide, Guide partially displays/flashes, Mini reboots... After it restarts I get to go through the above - TWO MORE TIMES...
Power cycle the Mini and it seems to be working - for now. So much for QC and stability.
Oh, and please stop putting up Welcome to your new guide screen that I have to skip out of. Why you all feel the need to keep reminding us about the debacle that is the new Guide/update is beyond me. Fix it.
