Man, I've been discussing levels on two groups for the last two days and I'm getting a bit fatigued. :-) I guess I'd say that in my experience, the Tympanis will rock, but the MMG's won't, not without a sub, anyway. On classical, the MMG's can sound strained on large ensemble material if you listen at natural levels, but not at typical home listening levels, which are lower. The Tympanis cut though natural levels like butter. But these days, I don't listen to anything at those levels.
I guess I'd add that while long-term 120 dB levels are hazardous to your ears, short-term 120 dB peaks are pretty uncommon in classical music and very brief and so probably won't harm your ears unless you're a musician and exposed to them all the time. A concert grand for example produces 120 dB peaks up close. So it isn't as extreme as it sounds.