Hi AmTrax,
U mean mono MC275's vs MC2000?
If its the older version of the MC275 SS, well, I did have the exposure. However, its NOT a direct comparison though as the MC275 went out (with regret) way before I had the MC2000, about a year later.
Based solely on memory, the MC2000 is the better amp in looks (of course), smoother musical performance and delivery, especially in the the bass although 2 MC275 SS specs seem to be some 20 watter more.
However, never did have a chance to do a DIRECT comparison as them my resources were limited and I had to move on with my upgrade urges.
Cheers!