Sure. I'll likely post about this again later today, as I received the AV8805 yesterday. I haven't had a huge amount of time to put it through its paces yet, so these are initial thoughts.
On sound quality difference between the 8802A and 8805 - I doubt there's any audible difference pre-Audyssey.
On specs difference other than Audyssey app (which I'll come to), for me the big ones are firmware eARC upgrade; future HDMI 2.1 upgrade; and future DTS:X Pro upgrade. Put those features together with the 8805's existing feature set, and you have the most fully featured processor on the market (although of course, others do better room correction).
As I mentioned, a major difference between the 8802A and 8805 is the Audyssey app. On the 8802A you're stuck with the default correction curves, unless you buy a pro kit. On the 8805 you can make your own.
Now, the Audyssey app is a load of tosh, but with 'Ratbuddyssey' (see
here) it can generate very precise curves.
Ratbuddyssey is essentially a programme for editing the files the app generates. It means you can use the same curves for all channels (crucial for integrating them), and edit the control points on a desktop. For example, I'm using the attached curve, which took me about 10 minutes to edit, match for all channels, and upload to the 8805. It's very straightforward. I need to verify with REW and tweak a bit, and then combine with sub filters I'll generate on my MiniDSP 2*4 HD.
IMO, Audyssey app+Ratbuddyssey+something like a MiniDSP 2*4, really closes the gap between Audyssey and Dirac/other room correction. It provides a lot of flexibility. Unlike the units featuring Dirac though, the 8805 (like the 8802A) works perfectly and reliably out of the box, without any bugs.