B&K amps are warmer sounding than Rotel amps IMHO. They are warm, yet detailed with a full bodied bass and a solid bottom end. With Paradigms B&K would be a better match than Rotel, IMHO but thats only because I like my sound on the warmer side. If you like more of a neutral sound then Rotel would be the way to go. So it all depends on what your ears like. Both are solid value amps that will get you very close to high end sound for a bargain.
You don't mention which amp you plan on using. I auditioned the Rotel 1066 directly against the Ref 50. The Rotel was using the Rotel 1095 and the Ref 500 the 200.7 both were playing playing through B&W Nautilus 805's. To me the B&K combination was a much warmer, detailed sound than the Rotel. I ended up with a Ref 50, however not with the amp as I already had another solution.
I was actually thinking of using a Rotel 1080 (already own it) for the front 2 Paradigm speakers and a Rotel 1075 for the rest. Now it is a question of a pre/pro or receiver as a pre/pro.
Or possibly, sell the rotel amp and buy the AVR 507.