Hi All,
From considering Ety HF3, MTPC, SE535 I actually went on to try the UE Triple Fi 10 and (to give on ears a chance) B&W P5. I also found the UE SuperFi 5 vi that I lost months ago in a bush!
First the SuperFi 5 vi... these, although they look almost the same as the UE 600 that I'm replacing, sound quite different to me (yes they still worked after having been outside for some time); they seem more detailed, have a wider soundstage and richer bass (though not overdone) - I actually really like them still, but the cable has some problems (if I move in the wrong way, I get cut-outs in sound). It may be their trip outside, but while they're working they seem much better than the dying UE600
The Triple Fi - I liked these but had issues with durability (in the space of a week). The first pair, the removable cable housing came out of the earphone body on one side, so I got a replacement, which worked fine for 5 days, then the right phone started cutting half its output (seems like the cable broke, because if I held it, it gave full sound again). I think I'd finally found a good fit on the last day I had them, and the sound seemed to have been improving throughout the time I had them; I liked the detail and texture of the bass (worked particularly well with cellos), and treble was quite good (the detail there was what seemed to be improving over time). I just didn't want to get another replacement set because I figured that I'd continue having problems with durability.
B&W P5 - Really really don't like these (they're going to have to go back from whence they came). Bass seemed to lack detail and was eclipsing everything else. The treble seemed to be both harsh and lacking in detail at the same time.
I'm now thinking maybe UM3X RC or one of the EarSonics (v2 of SM2 or 3). Can anyone comment or suggest any other options based on my experience above?
Thanks again