May I ask why you chose the X10 over the TF10 and EPH-100 in the long run? Might help figure out if the PFE 232 or IE 800 is the right step for you, or if a similarly-priced custom or other earphone would be better. Also, the IE 800 really doesn't isolate a whole lot, especially since it sounds best with a shallow seal.
I ultimately chose the X10 over the others primarily based off fit and comfort. I could never get a good seal/fit with the TF10 and EPH-100. I think out of all the ones I've tried I liked the sound signature of the EPH-100 and the JVC FXZ-200. But for me comfortability is a pretty high priority for me. I was also wondering if there are other IEMs I should be looking at in that price range. Thanks!