I found I liked the B&W better (but only by a hair). The M3 had better bass and a better sound stage, that was noticed on all tracks and right away. However the the B&W seemed to have more detail in the upper frequiences and sounded more natural on male and female vocals when hitting higher notes.
Having said that, the value of the M3 (and this is the 1st time I have ever heard the M3) is far superior over the B&W.
If money was no object, I would go with the B&W. For me and most people, money is a huge concern, the M3's win!
