Interestingly, I am liking the W3 *much* more than the UM3x. I realize that most people obtain a better fit with the UM3x, but not me. I prefer the gray silicone flex sleeves (in large) and they fit me very well with the W3 and I get a perfect & easy seal every time. With the Um3x, the longer nozzle tries to push the tip too far into my ear and this doesn't quite work. This ends up pushing the body of the headphones out of my ear after a minute. Going down to a medium size sleeve does not give me a seal so this bass becomes anemic.
I have no idea how people use the comply tips as they don't seem to work well on either the W3 or UM3x for me. I either don't get a good seal, or the ends of the tips get compressed and volume is reduced by about 50% (this happens almost every time I try them). My ear canals must be an odd shape or something.
Either way, the UM3x don't EVER sound as good as the W3 for me. I'm completely willing to accept that this is a fit issue since most of the forum members prefer the UM3x's sound, but there is no comparison for me. I either have a fairly muffled sound with good bass on the UM3x or unmuffled sound with poor bass/no seal.
So I guess I'll either sell the UM3x or spring for UM56 tips and do the comparison again. HeadphoneAddict, you're in COS, correct? Any recommendations as to a good place to order UM56 from locally and a material recommendation (vinyl, silicone, otoblast, etc) would be appreciated!