Firstly the Monster amp isnt too bad to look at but is too long to fit in the equipment rack, so I hide mine on the floor behind subwoofer. I definitely turned off the stupid power rating lights.
As for 3 vs 7 channels, I think there is also a matter of putting your dollars where the money counts. The front 3 channels carry well over 60% of the music and movie information/load (power wise). It is a marketing ploy from manufactures to sell that you must buy 7 channels of equal amplification.
I sold my Outlaw 770 channel amp and put less money (per channel) into the back 4 speakers and more into the front three. 2 used Parasound HCA-1000A amps for rear 4 channels, amd the Monster MPA 3250 for the front three.
I defintely like the Monster/Parasound setup better than the 770. I did make extensive comparisons on the Parasounds to the Outlaw and found the Parasounds a better match to my speakers. Better bass and highs, mids slightly better on the outlaw. Must wider sound stage in two channel music on the Parasounds! I sold the Outlaw before buying the Monster, but find the monster better in all regards to the Parasounds.
For the $800 price tag on the Monster (new on e-bay w/ 2 years warranty), I have absolutely no regrets making the switch.