Bryston 3bs Bridged versus one 4b

Has anyone had experience with comparing Bryston 3bs in bridged mode to a single 4b? I am currently using 3bs bridged for my Accoustat 3 panels with an Audio Research SP8 preamp and am considering a 4b as replacement. My main consideration is whether this would be a sonic improvement or not. If anyone can help it may save me some effort and/or money. Thanks!
Bryston does not recommend bridging their amps to drive Acoustats. The Acoustats present too low an impedence. I asked them this very question when considering amps to drive my 2+2s and ended up buying a 4B-ST, which I'm happy with. My preamp is the Audio Research LS-16, so we have very similar systems. Don
Thanks for the info Don. I recieved the same advice from Bryston's service tech when one of my 3b's was in their shop for repair.(diodes that were repaired while I waited) Judging by your choice in equipment you are obviously a man of superior intellect!