I actually never heard of Westone before this thread -- but from what I gather so far, it seems their physical attributes reasonably match what I'm looking for -- ie, the hardware sits fairly flush in the ear (which should hopefully reduce wind noise when on the bike, yes?) and the cables are well-designed and handle microphonics relatively well (so that should help when I'm walking around).
So, if Westone is indeed right for me, is there a smart way to pick between UM2 and UM3X (or perhaps some other Westone)? Does it matter one way or the other if my source will mostly be the Clip+? (which, imho, is a nifty little gadget)