My buddy uses the XXV, and I have the 880, unfortunately I haven't spent enough time w/ the XXV to compare the two directly, but I have used my 880 for over a year.
The Auto TA/EQ feature works very well. I did everything in my ability to get the TA perfect, but compared to Auto, it was a night and day difference, the auto was so much better.
The Auto EQ on the other hand, I could live w/o, it overly bloated the midbass region so I turned that part off and just eq'd it my self to my tastes.
Also, a few things that people don't mention, not only is there the L/R independent eq, but you can also independently adjust the crossover points, slopes, phase, and level between the front stage, IMO it would take a good amount of time to get that dialed in perfectly, but it's another feature the 880 has that I'm pretty sure the XXV does not.
Hope this helps some.