If you're thinking about the Onkyo TX-RZ1100 then you should also consider the TX-RZ920. It has basically the same capabilities and it's newer (only major difference I can see is 135w/ch instead of 140; both are digital amps / 5.2.4 expandable to 7.2.4). The major reason I'd lean towards the newer unit is that in my experience there appears to have been a massive improvement in AccuEQ with the newer models.
I recently had the opportunity to use both a TX-RZ810 and a TX-RZ920. I originally purchased the RZ810 but then decided I wanted to do four height channels instead of two, so I returned it and bought a refurbished RZ920. The AccuEQ on the RZ920 works a lot
better than on the RZ810. On the 810, it wouldn't accurately detect the distance to my sub or center channel. For some reason it thought my center channel was at 4 feet, when it actually was at 12 feet! The sub also gave some weird result like 6 feet when it was at more like 15 feet. On the 920 all of the distances are accurately detected.
On top of that, the AccuEQ routine on the 920 is much more involved. On the 810 it just briefly cycled through pink noise on all of the channels. With the 920 the EQ process takes probably 3-4x as long, with multiple different tests, and like I mentioned before it works a lot better. I think the overall sound balance with the 920 is also much better than the 810. With the 810, bass seemed really overemphasized and just weird somehow--I think it just wasn't doing something right considering the odd distances it was giving to the sub.
I've never used Audyssey, so I don't know how it stacks up, but I suspect the differences between them has been cut down with the newer version of AccuEQ.
Granted, the 920 is a more expensive receiver, so I can't completely rule out that it has a better processor, and that is what's responsible for the better calibration program rather than it being newer. All I know is I'm glad I switched over to the 920 from the 810! (I actually have a RZ620 on the way for another room, so I'll see in a few days whether it has the better calibration program.)
For what it's worth, you can get a refurbished TX-RX920 right now from Accessories4Less.com for $900
(the 1100 costs $1000
from the same place). Just something to consider.