Darrin,
You do understand that you only gain 3dB's in volume when you double your watts (going from 90 to 180watts)? So if you find a receiver that puts out around 135 watts, versus your existing 90 watts, your only gaining about 1.5 dB's which is minimal.
HDMI features is important, as would be the latest Audyssey MultEQ XT, Dynamic Volume, and Dynamic EQ features. Keep in mind, Denon should be coming out with new models as well soon. The 2809 is also a killer receiver loaded with options.
If you don't have much room behind the seating area, you would be better off just going with 5.1 and placing the Qs8's slightly behind the seating area on the side walls, not the rear walls.
