I know we've strayed a bit from the OP's original question, but I have a number of speakers at home including a pair of CS3.7s I run on a pair of 7B SST2 amps, and the sound is just magnificent. I had a pair of 28BSST2 amps for a few weeks between trade shows and there was most certainly an improvement, but it was not a night and day difference.
I remember doing lots of trade shows with 28BSST2 amps, and the earlier SST version when it was first released using 3.7s, and we always got sound that was to die for.