Ok, took delivery of the 7b sst2 .In a word, the B&W 800 Diamonds are simply stunning with the bryston bp26 and 7b sst2 mono blocks. The 4b sst was good with the 800 diamonds but the 7b sst2 are truly something very very special.I really only expected a small difference in the bottom end. The difference was of course substantial in the lower registers( more than even I expected) .When the bass is so well controlled it just seems to improve everything else across the spectrum.I simply wasn't prepared for such improvements in the mid and upper registers.The combination has produced some of the best midrange I have heard.When it comes to high frequency reproduction it is definitely the best I have ever heard from any system,period( imo) .