I don't know where you are looking, but A4L has the Denon 2100 for $70 less ($330) than the 2200 ($400) (and the Yammy 850 is $470).
Are there features on the 2200 that are important to you? As a music guy, I would get the 2100 allowing more money to go to speakers. I don't think you care about atmos and that leaves HDMI version 2.2 as the only difference I see. I don't plan on installing a 10' projector and am pretty sure that I could not tell 4k resolution on my 60" screen from 15' back where the seating is.
From an Audyssey standpoint here are the differences. Going from Silver to Gold has little value to me:
As for the difference between XT and XT32, see the chart at the bottom here:
http://www.audyssey.com/technologies/multeq/flavors
If you level-match dual subs and set their distances close to the same, you have done what Sub EQ HT does.
So the main benefit of XT32 is 4 times the resolution for EQ'ing your subs. That sounds like a lot, but the 128x of plain XT should take care of the big problems. I suspect there is a situation of diminishing returns by the time you get to 512x, but honestly don't know that to be fact.
If you go the Yamaha route, make sure it has decent sub EQ as that is really where EQ makes a solid impact.
You may have noticed that I ignore Audyssey's resolution on satellites. I just don't really care much about that. It is fun every now and then when I hear something come from my satellites watching a movie, but I have never even considered critically listening to my satellites in normal 5.2 operation (I have listened critically to them only as mains for stereo music). But if you are a HT guy, that may be worth considering.
Re-read this section of Hi Ho's post:
Audyssey uses FIR filters and works in the time domain to correct issues. It is also the only system that actually EQ's the low bass effectively which is really one of the most important areas for any room correction system. The competitors are simply automated parametric equalizers which are not as effective and none of them do much, if any for low bass.
If Hi Ho is correct (and he usually is) and if you plan to have a sub or two, I don't see Denon vs Yammy as a difficult decision!
It is a shame that Yamaha hasn't developed a similar system or just paid Audyssey as I do like Yamaha.
Also, you may want to consider the Marantz SR-5007 ($350 at A4L). Marantz usually falls short overall on HT features against Denon, but even the lowly 5007 has 7.1 RCA inputs and pre-outs for all 7.2 channels. If you have no use for them, go Denon.