Which models of Dynaudio would you be pushing? I have no hands-on experience with the Bryston, so unfortunately, I can't give you any comparison. I have owned the Krell KAV500 for a couple years now, and for the last year have driven Dynaudios with it. There are a lot of detractors on this particular amp - not really a Krell, etc. I think it's a great HT amp in general. The Dynaudios sounded good, but then I bought a Krell KAV-250a for the L/R fronts and that really brought them to life.
Bottom line - if you're driving a set of Dynaudio monitors, it's probably a good match. If they're the bigger speakers, it'll sound good, but you really need more amp for the bigger Dynaudios. I doubt the Bryston would be much different since it's rated approximately the same. You can get the Bryston for a bit less money, and that's probably wise, though the Krell / Dynaudio combination is a really nice one. -Kirk