Do it ! I vaguely remember getting the impression that the B2's were more mid oriented then I was looking for. I picked up M2's awhile back and can say I'm very happy I went with Brainwavz. Build quality is great. Sound wise, though the M2 might not deliver the "audiophile sound" some look for, they delivered just what I was looking for. Give me a neutral sounding IEM and I'll EQ it to death. I just wish I had a better mobile source now.
Hopefully the dual armature's dedicated tweeter will give me highs that don't sound like they're coming from a tin can. (Looking at you meeelectronic generic IEMs )
What really convinced me i wanted these was the speed. I cant listen to metal or fast electronic with my AD700s, they just are far too slow. I don't mind the downplaying of bass registers, but if it makes an intense piece sound relaxed, thats unforgivable.