I also feel that while the Onkyo/Pioneer/Integra are more capable for 4 ohm nominal speakers, the Denon 6800 and Marantz Cinema 30 will likely have better preamp/DAC/DSP performance. At their current price points, the O/P/I models, are much better deals, ignoring the reliability part that is really an unknown quantity for the time being. On money no object basis, the Marantz C30 would be my choice though, I am sure it won't "sound better" on all else being equal basis, but its build quality looks to be the best among the few mentioned, probably only best by the more expensive Denon A1H.
Anyway, this may be the best time in a long time, for those looking for near flagship/flagship AVRs, as there are finally quite a few choices. Wait another 6 months or so, Yamaha may join the group, hopefully.