The spec sheet for the 3808 shows Fronts L + R, Center, then side surrounds L + R and back surrounds L+R and they do state "Identical Quality and power for all 7 channels". I know this is not the same as a true all channels driven spec, I think H/K is one of the few that reports in their specs an all Channels driven rating, at least on the avr146/154 I just looked at.

I did look at Sony's spec sheet for the STRDG820 and no where do they state identical power, they just say it has 710W available and the specs only show 2 channels driven and a spec for 10% THD into 5 channels \:\( .

It does take some reading between the lines.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70