Many prefer separate power amps over receivers because most receivers don't really give full rated power into all channels. I don't have a multichannel setup, but that's the way I'd go if I did, and congrats on making that move. It looks like you're having success doing it as well.
You mention the Emotivas as sounding clearer and detailed at low volumes. What other sonic characteristics might have changed? Would you say the sound is smoother also?
VPI, Grado, SME, Pioneer Elite, Magnum Dynalab, Oppo, DVDO, McIntosh, JJ, Mirage, Kimber, Transparent, MIT, Pangea, Wireworld, Shunyata, PS Audio, Furman, Sanus