I would also check with Klaus. If they are upgradable at reasonable cost this is a "no brainer". Hands down the mono's sound better than the Bryston 4B-SST IMHO.
Is your "hand's down" no-brainer assessment based on actual listening between these two amps or did you just see a picture of the Bryston? I'm not saying one sounds better than another, but I would love to hear the reaction of Odssey followers if someone came to this board and said Bryston was hands-down better than Odyssey...without ever hearing the Odyssey.
Anyway, I would suggest a demonstration and direct evaluation between the two amps. Both are high quality and I believe I have heard Klaus say on more than one occasion that "system synergy" plays an important role in sound quality. Maybe the Bryston has better synergy with this guy's system, maybe the Odyssey does. Only one way to find out and it involves listening to both on the same system. Perhaps a more useful approach is to see if anyone in the area has an Odysey amp that can be directly compared to the Bryston. It would be useful to more than just the gentleman with the question. I would like to know!
Jman