I haven't heard these in the same system with the same speakers as you had requested, but I have heard them both. This is an easy one, Get the Bryston!
I would consider Bryston Class B
and Adcom Class C based on the Stereophile rating system.
You may also like a McCormak, as it has better midrange than the Bryston, however not as deep bass. So it really depends on the speakers you plan on hooking them up to.
Rich