All solid state receivers should be designed to be sonicly flat from 20hz to 20khz by design, so there would be no reason to believe the Onkyo would not perform like any other decent AVR on the market with similar specs.
The only speaker in the Axiom line up that has had issues with certain receivers in the "past", was the m80's. Even then, any receiver can drive the m80's, it is just a question of how loud before the receiver might possible go into protection mode when driving the 4 ohm speakers.
There is no reason to believe any receiver would have issues with the m2's.
