I had Klipsch KG-4's in the 1980's for a while. I have had M60's for almost ten years now. I have not listened to them side by side.
Since you are accustomed to the sound of the Klipsch, I think the Axioms will present a bit of an adjustment for the reasons already mentioned. The Axioms are more balanced, more linear and more detailed, IMO. They are also much less efficient, but just as capable of very high SPL (especially with the models you've chosen).
I enjoy listening to many different speakers, and try hard not to frame the experience as uniformly "better or worse".
I hope you will enjoy the new speakers. I am envious of your amp!
