I've wanted to switch to Directv for years now (once I realized that Dish would never get Sunday Ticket), but never did solely because of the DVRs. The 24s are what got me over the hump. Moved from a 622/525 setup (with the second outputs on both DVRs fed to the entire house) to 2 HR24s and 2 H24s 2 weeks ago, and I really can't see anything that I miss from the Dish DVRs. I don't notice any difference in response time, the search functionality works better, and I even got adjusted to the guide. The pausing on the H24s isn't an issue since we only watch DVR playbacks on those. As a bonus, I discovered that the small TV I have in my office that a relative gave me a few years ago is actually HD!
The challenge for me is getting the wife and kids over the learning curve and understanding how MRV works. With the Dish DVRs, the 622 was for my recordings, and the 525 was the wife's (she watched most of her shows in the bedroom on an SD tv, which was swapped out for an HDTV as part of the move to Directv). There were shows that we both liked which ended up getting recorded on both DVRs, so we never had issues. With MRV, we can just record a show on one DVR and watch wherever, but that's where the problem comes in. With MRV, you can watch recordings from a DVR independently on two of the boxes, but one of them must be the DVR where the show was recorded. So I get situations where I'm watching something from the bedroom DVR on the H24 in the office, and my wife wants to watch her soaps in the family room. Because I already have the bedroom DVR in use, she's blocked out of watching in the family room and can only watch on the bedroom DVR. I also find times where someone may have paused a playback in a room and left to do something else, which also locks the DVR feed and I end up having to run from room to room turning off the boxes. We really didn't lose any functionality since you could only watch two outputs from the Dish DVRs and one of them was the room where the DVR resided (and the other had to be SD!), but the concept of being locked out of the DVR takes some getting used to.
One other thing I've noticed is that the RF remotes on the Direct boxes work much better than Dish's UHF remotes on the 622/525. I put one of the H24s in the basement with a channel 3 converter and fed my son's TV and 3 others that don't get much use. The Directv RFs work flawlessly, where I found myself having to point the Dish remotes at a certain spot and having to press the buttons multiple times to get it to work, even with that DVR being 1 floor closer in the family room.
So the bottom line for me is that I have a learning curve with the family, but I'm not looking back and can't wait for football season to start!