Sorry Guys,
There are prob. several like me, since the Outlaw combo is such a good deal when making the leap to separates. So I have no 'comparison' data valid to your issue.

I had a Pro Logic receiver, and installed new speakers, new cable, new Satellite, 950/770 all at once.
I can tell you (not having had one in a jillion years) the setup and performance of the 770 seems flawless moving from a receiver only. Plenty of power, the boys mentioned they cranked the sub all the way up (idiots) and put in something like Matrix, (which sent the sub into protect mode). 2 Surrounds are still not hung, as we are contemplating rearranging the whole room to accommodate new Monitor/furniture etc.
This little set of speakers in the 5.1 array right now has more power than they will ever require of the 770. Runs warm (but not hot) after hours of use, in an open rack with about 6 inches clearance.
My speaker array was my first purchase, I would have gone with something larger if I had researched before that purchase. Definitive Tech. 7.1 set of basically the bookshelf range, Pro Cinema 100's with a 1-step upgrade on the Center channel, and sub. Sensitivity of (I think) 98.
Nothing here valid to your issues. Just Posting that I’m happy with the 770.