Would switching amps make a big difference?

Don't know what amps work BEST with ML speakers, but I had a pair of Rogue M150 monoblocks running ML Aerius i's with no problem. I currently have the PrimaLuna Premium HP amp powering the ML Electromotion ESL's, again with no problems. 

+1 Al and Atmosphere

Al is (as always) correct about the Music Reference RM-200 having an input impedance of 30K balanced. Roger Modjeski did that for a reason, but will change that impedance to anything you want. I assume there will be a price to be paid (sonically), but I don’t know what it is. Give him a call if interested. Or get a tube pre-amp that is happy driving a 30K load.

I've owned the 11As for going on 2 years.  Currently, I'm driving them with PS Audio BHK 300 monoblocks and I simply could not be any happier.  Highly recommended! 

atmasphere,
Let me elaborate on your statement, "since solid state amps tend to double power as impedance is halved, right away you can see that the MLs will be a bit bright if the amp actually got away with that."  Actually, I think that although the SS amp has the capability of providing 2x the power as impedance is halved, the SS amp is still flat in freq response at any given moderate power demand for higher impedance.  For example, a 200 watt amp capability at 8 ohms will still output the same power across all freq below 200 watts.  I would be wrong if this SS amp only puts out 100 watts at 16 ohms, 50 watts at 32 ohms, etc.  What do SS amps usually put out at these much higher impedances?  If my numbers are correct, then for an electrostatic whose load varies from 32 ohms in the bass to a fraction of 1 ohm in the HF, the sound below 50 watts of output would be uniform across all freq, not bright.