Sorry, can't give you any real help, have not heard any Polks recently, but I have found the Axioms(M22's) to be cleaner, clearer sounding than the older Polks I have heard.
Just wondering what price you are looking at for the polk's? The website states $550/pr.cdn. The M22's are $520 or $468 from the factory outlet. I will guess your price on the Polk's is about the same as the M3's otherwise you wouldn't be asking about the M3's. But you say you are thinking about the M22's later, if you can swing them I would recommend them with out hesitation.
Check out the Hearing Things forum to see if anyone near you has some Axioms you could audition and go from there.
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