Those are all pretty different-sounding. I would say that for bass you'll want at a GR07 Bass Edition over a regular one. The BA200 and R-50 have less bass than these. The R-50 especially is not a good buy if you want an upgrade in bass quantity from the RE0.
The MA750 has a lot more bass than the other sets you're considering, it's a borderline basshead earphone. Good in that context, but very different from an RE0.
The MA750 is bassier and warmer, with less forward mids and a bit more lower treble. The R3 is more balanced overall, with less bass enhancement, more forward mids, and smoother treble.
GR07 Bass Edition can be had for ₪453.86 () or so nowadays. It has slightly more bass than even the Fidelio S2. The midrange is better on the BA200 IMO but I think the GR07 BE is a worthy compromise if you thought the B2/VC1000 didn't have any bass. The RE-400 is most likely not a good buy for what you want.
Thanks so much for the reply, and for this amazing thread.
- Can you comment regarding "sony-ish" sound with comparison to the main candidates above?
- Should t-peos altone2000 should be considered in this category?
Edited by ziflingus - 8/19/14 at 6:47am