David, the N3 sounds like M3 and the N2 sounds like M2. That's it a nutshell.
The N3 will give you a "fatter" sound with more bass. The N2 has a lighter touch on the bass.
I have both and don't find one "better" than the other. Sure the N3 goes louder and lower but the N2 is just as satisfying.
BTW, this is as it should be. Whether you buy a cheaper/smaller speaker from Axiom or a more expensive/bigger one, the satisfaction is the same as long as you operate it within spec. My M2 gives me as much satisfaction as my active LFR1100.
Note the button interface is nicer IMO on the N2. The N3 has the door in front that can be difficult to open.
