The 'S' in the sound has not much to do with room acoustic, even though room acoustic plays an important role in sound you hear. I think the tweeter in M60 is a bit harsh, but at its price, M60 has produced pretty darn good sound.

I have a chance to listen to B&W 703 at my friend's house. I must say that the high is very natural and smooth. I play the same CD from Diana Krall and B&W 703 has better sound. Note that a pair of B&W 703 costs $3000 and a pair of M60 is only 900.

I put Musical Fidelity X-10 V3 in between rotel CD player and rotel pre-am and the S's in M60 reduced a bit.

all in all , M60 is good speaker, but i think i will update it soon. Aperion is on my list too, and of course, B&W.