As a general matter with amps, it has been my experience that the lower powered amplifiers in a manufacturer's line sound better to me, except in the case where you're driving a speaker that needs more power or current. Maybe it has to do with the signal passing through less amplifying devices? In the case of Krells I owned, my old KSA 50 MkII was the sweetest sounding one I owned, beating out the KSA 80 I owned and all the higher powered ones I listened to at the time at my dealer's. And having heard the Krell 50S and 200S, on the same speakers, I felt the 200S to be probably more neutral but clinical, pretty unremarkable really, while the 50S seemed to have a little sweeter character and seemed less fatiguing to listen to (keep in mind that I am now a tube guy, and it may well be that the 200 was a far more accurate amplifier, but I seem to like a little coloration from time to time). But neither my KSA 50 nor the 50S could drive the Duntech Sovereigns nearly as well as the big KMA or KRS200 monoblocs, as the less powerful amplifiers could not control the woofers nearly as well nor provide the dynamic headroom that the Sovereigns could deliver. So I think that the answer to your question of which amp to choose will hinge on the speakers you choose--if you like the sound of the KSA 50S, try to get a speaker that matches the characteristics of the Totems you owned.
