Welcome to the forums! You will find that a lot of people here really love their M60s and M80s. I have M60s, but I have also heard the M80s. With the 80s (the speakers, not the decade), they seemed to produce more low end, and can be driven harder. That doesn't mean that the M60s are any slouch. Since most of us have powered subs, the real low end gets split off to the deep frequency duty anyway, and how loud do you REALLY need it. I used to watch movies with my family at about -14 on my receiver, and if it was an action flick where I like it loud, I would turn it to about -8. The loudest I've ever turned it (yes, just to say that I could) was to 11. My receive (and the Axioms) could keep going, but it was really not enjoyable for any length of time above 0 or maybe 2. Just too loud, although nice and detailed and clean.
So, I would say, jump up to the M60s if dollars are a concern. You will also want to look at a possible new center channel if possible. The upcoming VP160 would be a great match for the M60 fronts, or the VP150 or the monstrous VP180. You will get a lot better front sound stage.
Just my 2 cents.
Good luck and keep asking questions.
