I owned Monarchy SM70 Pro monoblocks, and they were definitely on the warm side for SS amps. They'd have similar power as your MC275, and so would probably drive your Sehrings to similar levels. They're Class A and run hot, but not blazing. I loved them with my Von Schweikert VR-1s, but they were a little noisy with my Druids. The new Mk IIs are supposed to be quieter than the originals I had.
David
David