OK, so my DirecTV install went down yesterday and these are some pretty fresh observations. Obviously the most important thing, picture quality. In the limited viewing I've done thus far (mostly all sports) I can't say there is much if any diminished picture quality. The picture 'may' be a touch softer in some scenes however it's just as sharp as FiOS was. Great clarity, good skin tones. I haven't bothered check out many SD channels, just not that into it given it's 2011. SD isn't bad though, obviously it doesn't retain the same levels of sharpness but it's certainly watchable. As of right now, I have zero regrets switching, we'll see if that remains that way after a month or so but so far - so good.
Here's the other side of things though. I got the whole-home DVR which is awesome. Absolutely love being able to utilize this, it's seamless - no lag what-so-ever. It's going to be nice to be able to record kids shows for the little one and have them play in her her room versus on the big screen downstairs!
PPV has not been utilized, nor do I see us utilizing it at all given the netflix subscription and bluray at redbox.
hardware. I got the newest HR-24 dvr box. It's much faster than the standard silver motorola verizon box I had with FiOS which seemed to lag with commands. the HR-24 reacts immediately to all commands which is a major breath of fresh air. It's a good piece of hardware. The will be releasing the HR-25 soon a well.....not sure about the specs of that though.
GUI interface is certainly behind the times though, this is the one major disadvantage of DirecTV that I've found thus far. Rumor has it that the GUI will undergo an overhaul this year though and go HD, if not totally redesigned as well. It's certainly workable, just a dated. The FiOS GUI was more advanced and possibly a little more intuitive. I'm not one who reads directions, I feel that I'm tech savvy enough that I should be able to pick up the remote and get what I need done easily. If I can't, how can I expect the lady to figure it out

In all seriousness, FiOS is much better in that regard. However, my tone may change as I put more time in.
That's basically it I think......Any questions specifically feel free to ask. I want to be respectful and keep this thread FiOS however I think we all know it's a sinking ship so hopefully we're all able to use this thread to help each other out with the other viable service options.....