We are relatively new to FiOS and like most of what we are getting, particularly the multi-room DVR.
If there was one Comcast-like DVR feature I would like FiOS to ad it would be this:
When fast forwarding on the DVR, be it a recording or just catching up on the buffer, when the PLAY button is pressed, the DVR screeches to a halt and backs up a few seconds (the number of seconds depends on the speed (2X, 4X or 8X) at which you're FFing).
So, if you're FFing through ads at 4X, you suddenly see your show is back on, you hit PLAY, and the DVR actually starts playing a few seconds back so that you don't miss that little bit.
I must add that the "jump" buttons that jump 30 seconds either way do the job fairly well. Hit it 6 times to skip the ads, then a 7th is into the show so jump back and watch less than 30 seconds of ad.
The 30-second jump button is awesome for fast-watching NFL football when you're in a hurry. The moment the whistle blows on a play, hit the 30-second jump button and presto, the QB is about to snap the next play! 
