I had the Adcom and the Bryston 7Bst, and 7Bsst2 (super Stewart Taylor after the inventor). I have never owned a 4B in any iteration but I can say that the 7Bsst was warmer and faster than the Adcom. I drive Maggie 3.7s- the first gen and the X. For my liking the Bryston solid state sound is better than my Pass 600s were and better than the Audio Research VT130 was (mostly because tubes can have flabby bass with Electronica). If you have low efficiency speakers and like volume Bryston has the guts to drive them hard for long listening periods.
