The itch did not stop, and I called Axiom a while ago today. The nice person at the other end of the line told me that I would not hear any difference in sound going from 60s to 80s for my conditions (I explained him my room, gear etc. in detail), unless I had them running in 350 wpc power amp.

I have to admit, this was what I wanted to hear, and I will gladilly hold on for now, saving my money, and enjoying my M60s.

Axiom M60s, QS4s, VP100 Onkyo TX-SR804 Oppo 970HD Rotel RB-1080/RCD-1072 REL Q150E sub, PS 3