The Matrix M-stage is ok for the LCD-2, I don't have other amps to compare it to but I feel the treble can be improved a little bit more but the bass is well controlled and defined like nothing I've heard before. This combination is definitely excellent for all kinds of rock music. The gain switches also affect the sound quite a bit. I put mine on +10db, thats where I like it most. My M-stage is also with the Class A biased OPA627.
Recently I just changed my zero dac to a meier stageDAC and boy the music sound so much alive now compared to the zero which sounded dark.
My next upgrade probably get a Meier Concerto or woo audio WA6