Since you are interested in ARC, and have ARC gear already in line, why don't you ask your dealer to allow you do demo the DS450? It doesn't have the glamour of the tubes but it has plenty of power and designed completely in house by ARC. I have a REF 3/VT200 driving 3.6Rs and couldn't be happier, but one of these days I'm going to listen to the DS450 just out of curiosity.
Amplifier for Magnepan 20.1s
I currently have Magnepan 20.1 speakers driven by Pass Labs X250.5 amp with Audio Research Ref 3 Preamp and Ref 8 CD player. Pass Xono phonostage, VPI ref superscoutmaster/Dynavector xv1s cart. My room is 16'W X 26'L X 10'H. I have a dedicated 30amp circuit breaker for this room only. I am considering changing my amplifier. Should I upgrade to the Pass Labs X350.5, X600.5, or should I go with the Audio Research Ref 210s (since I love the sound that was created since adding my other Audio Research products but the Ref 610Ts are out of my range and also would probably draw too much power for my circuit to handle). My only concern: is there enough power to produce a dynamic sound that wont go mushy in the bass? What should I do?