Jon -
for what it's worth, I drove my M30s with a McCormack DNA-1 (full Rev A) and a ss McCormack pre-amp. It made for a very balanced presentation from top to bottom, with good control and grip of the lower end. My only concern with this ss set up is that I think the M30s can sound a little forward and a touch resolving/analytical. Tubes may help add some warmth - admittedly the soft dome tweeter of the M30 is a treat which helps and, distinguishes it from the Super HL5 or the 7-ES.
Btw, there is a DNA500 on Audiogon with the Ultra mods at very, very fair price.
The M30 a great loudspeaker, especially for vocals (my wife loved listening to a Dianna Krall sacd on the M30s).
good luck,
Peter