It is my understanding that the m22's are much more detailed than the m50's. I think the general opinion from most board members is to stick with the m60's or m80's when buying towers. I know several people on here really love the m22's.
However, with the m22 you will want to consider a sub such as an ep350.
if you order from the factory outlet you can save an extra 10% too, so maybe that would help you if you decided to go with the m60's instead.