R2K, it might depend on which sensitivity numbers that you're comparing. Axiom lists both anechoic numbers and also in-room figures which are 4dB higher. Typically, in a live listening room the sound from the room surfaces is about equal to the direct sound from the speakers at that distance, resulting in an increase of about 3dB above the direct sound alone.
From the numbers you mention it's possible that you're comparing the Axiom in-room numbers with anechoic numbers(without the 3-4dB added)from other makes. Most of the Axioms are actually right about at the industry average in the high 80s of dB sensitivity. The M80s are slightly above average in sensitivity(but ironically sometimes are viewed as if they required more, rather than less power), reflecting design factors such as the larger enclosure and multiple drivers.
