Mine was upgraded yesterday. Yippee! I didn't bother converting any timers -- I just deleted them all and started fresh. Too many times in the past there's been flakey timers after an upgrade, so why tempt fate with a major overhaul of the timer system?
I wanted to report that one of the worst causes (on my 522 anyways) of A/V sync and audio stuttering seems to be gone. Previously, if I started watching a program on TV1 that was currently recording, there would be horrible stuttering, chirping and sync problems. However, last night I recorded the finale of The Apprentice (3 hours) and started watching it 45 minutes after it started. I didn't get a single burp/chirp or hiccup for the remainder of the 3 hour recording! And to top it off, when it began, I had approx. 16 hours left which normally would increase the amount of hiccups.
So far, I'm pretty pleased with the upgrade...