I am having difficulty understanding what Crest, QSC and other boutique-y (non traditional?) power amps can do that a "normal" amp like a GK, Ampeg or Mesa cannot. I have always been an Ampeg guy, but recently bought a SansAmp RBI and can really see the benefits of a seperate preamp and since my Ampeg is only being used as a power amp currently, I would be interested in knowing what the fuss is all about regarding these power amps as they are totally foreign to me. BTW, are these Crests and QSCs built for bass specifically? Thanks!