Every amplifier I ever auditioned has some sonic signature that seems to be highlighted in one area or another of the audio spectrum. Ideally it should be balanced and neutral. Naturally Krell is famous for the bottomless bass and very articulate bass at that and everything else.
I exist in the midrange of audiophile world and I have come to find that Bryston amps,the older 3B,4B models and possibly the newer SST models were very prevelant and articulate in the low bass and mid bass range. So noticable if fact that it was shocking! I had settled for what I consider a well balanced amp, an Aragon 4004II amp that has quite acceptable bass and a smooth open midrange and highs. I listened to a lot of amps in that price range let me tell you. I did not end up with the Bryston because I liked the high end of the Aragon better, but oh that amazing tight bass from the Brystons!
If you can afford the high end estoteric get the Krell, but if you want the bass at a limited price point it is worth considering. Perhaps other Bryston owners may chime in. Many folks that biamp use the 2b,3b, and 4bs for the bottom end of their systems.