I've been using a pair of Meelec M6 on the gym for 1year and a half and although they are very durable (still functioning perfectly) i absolutely HATE the wiring. It's very uncomfortable and the only way i can seem to use them is to clip them to my shirt or shorts and even then i have to adjust them frequently. The whole wire is very stiff and doesnt seem to "flow" naturally retaining the curved shape from the carrying case.
The M6 have been through some revisions since then so they might be better now, I can't really tell.
I've taken a picture to show this problem. In the picture you can see the CX400-II and RE0 with the wire perfectly straight. The M6 has been stretched and I tried to make it straight but it just curls up how it shows in the picture. As you can imagine this is a pain to wear
I just ordered a pair of PL-30s to try and replace the M6 (didnt go for the E30 because sound quality is not really needed, i mostly listen to podcasts), i'll see how it goes.
Did you look at Sport Fi S6 ?