I've had FIOS TV for about a month now, and boy was I spoiled with my old DirecTivo!
One of the worst things with the DVR is that probably 2/3 of the time when I press a button on the remote, nothing happens! I've realized part of the problem is it seemingly only works in a narrow range of angles, but the main problem seems to be that when the DVR is "thinking" it gives you no indication! Every computer OS, and most other smart devices, have a spinning cursor or "please wait" popup that tells you the device is busy and you have to wait. Why was such a simple and basic feature left out of the FIOS equipment?