X-over points are based both on what your speakers are capable of in your room and by your preference. With any setup, there is a fuzzy middle-ground on x-overs where there's no "right" or "wrong" setting.
IMHO, 50hz on the M22's is too low.
http://axiomaudio.com/gallery_m22ti_diagram.html They start to roll off at 90hz and are at -3db @ 60hz per Axiom's specs. I'd adjust their crossover to at least 60hz, if not 80hz. I'd bump the M2 setting up to 80hz as well. Whatever you set the M22's, I'd match the setting on the M2's since they use identical drivers and have similar frequency curves.
The difference between a "Good" sub and a "Bad" sub isn't necessarily quantity, it's quality. A "good" sub will amaze you with not only it's prodigious bass, but its ability to produce that bass cleanly and to seamlessly mesh with the rest of your system.
Good luck!
