Did you figure out you're an analytical listener from your cx400's experience? Sorry, but LOL! I used it a couple of years ago and while it is one of the most decently and balanced sounding low-end sennheisers it's nothing special at all - let's say it had passable detail and clarity for the price but not so relevant nowadays, especially with all the cheap iems from vsonic, soundmagic, brainwavz, meelec,...... etc. that are way ahead in the game.
I dont think getting B2 is a good idea if you are not satisfied with MH1Cs signature. B2's and MH1C's share almost the same signature with minor differences according to these opinions..
B2 and mh1c sound nothing like each other.