Having used DVRs from day one, including a TiVo for several years, I can tell you that no NBR works reasonably well.
It's not due to the software, it's due to the listings.
For example, on Fox Soccer Channel, they started showing a new half hour magazine program called Premier League World. It is a weekly program, and they show it about 8 times every week.
The problem is that the listings for that show don't give episode numbers, or episode dates, or any other indication that it is a weekly show.
The other problem is that since Fox Soccer Channel has lots of live sports, they also have lots of programs that end up running late. Then the following programs are all delayed 10 or 20 minutes.
So, I basically have to record all 8 showings of the program every week to be sure that one of the 8 timers will actually capture the full 30 minutes.
That's just an example. (Other "fun" ones are when the listings person puts the wrong program title and so the DVR doesn't record the show - true life example, btw.)
There are certainly some advantages to NBR, but you still have to constantly check your schedule, and you are still going to miss stuff (see the ranting and raving about this in various TiVo Forums).
Dish's implementation of NBR is about as good as any (to answer your original question), and I'd rather have a 722 than any other DVR right now. (And you know that you will need to subscribe to HD to get one, right?)