I was never in the camp of 'separates sound better,' rather thought that compartmentalizing left room to make changes easier and would protect the processing boards from the heat of the amps (number one killer of electronics, afterall, is heat).
I find myself more in agreement with Peng re use of an AVR with preouts. I just wish the AVRs had better control of selecting amps to activate or not. When I upgrade in a few years (I presume), it will be an interesting dive to see how pre-pros change vs the AVR.
I think assignability of amps to binding-posts and selective use of pre-outs on an AVR is key to usability in the future... making it easier for people to understand and customize to their needs at the same time.
*shrugs
"that's just me; I'm a different breed of cat." ~Dennis Miller
-or-
YMMV