I like the sound of the W4 with the long Comply tips more than the standard ones or other types, but the tri-flanges. Perhaps the X10 is a bit more fun and kind of richer in the midrange, with more bass presence, but both are enjoyable IEMs to these aging ears. All Shure IEMs I've tried sounded to me between harsh and annoying, none was really enjoyable. Haven't tried the 535 though, maybe these are different, Tyll likes them