^^ Well, if you've read all 4 pages (not a lot) of this thread, you'll see that right now it looks like the UM3X may have that little extra edge over the CK100 -- see last few posts. I'm still waiting to get my UM3X replacement to make a final decision.
All this is very personal and I don't claim to have the 'right' answer for you or anyone else. Having said that, I find quite a few of the claims made about the merits of the SE535 & SM3 to be result of hype and the novelty factor (+ aesthetics in the case of the SE535).
I also think, and I haven't said this before, that I think more people (the general public) would find the W3 a more appealing/ exciting IEM than the UM3X & even more so than the CK100.
music, I'd like to personally thank you for saving me and my wallet from any unnecessary strain.. I love my W3's!!