I lived with a pair of M3si's for years which are about the same efficency as M1s. I owned and used several tube and solid state amps. Here is my experience.
tubes:
Quicksilver m 60's monos were nice and smooth, but so underpowered that at "realistic" volume they gracefully overloaded causing loss of definition and dynamics.
VTL 185 tube monoblocks, better match than quicksilvers, but still not powerful enough
Music Reference RM 9 stereo amp, the only tube amp that drove the Mirages well
solid state
Classe DR3 class A stereo solid state 25 watts (really about 250) was an exellent match
Bel 50 watt class A stereo, 200 watts mono, two amps were perfect, but one was simply not enough power.
Conrad/Johnson 2300A stereo class a/b 250 watts very good match w plenty of power, the 2500A at 300 watts was even better