No specific site, but I'll Google a pair I'm interested in and see what reviews are available - Amazon reviews and easy-read reviews from subjectivist sites like What Hi-Fi I ignore. Basically, if they go into detail and take some measurements I'm inclined to take them seriously.
The Shures I mentioned and the IEMs you're looking at are similar in a lot of respects, with boosted bass and accentuated treble. This is not generally a good thing, though a lot of people do like that sound. The Shures manage to keep things in check though by having a more gentle concave slope from the mid to low bass region, and roll off the highs sooner. The E10s sacrifice midrange (which is where the music primarily lies) in favour of a steeper concave slope toward the lower bass region - highs do extend further though. Then there's also the Shure's ability to switch out cables along with better sound isolation.
EDIT: 1st prize of course would be the ability to live with both for a while, because truthfully fit is a key element in whether or not a pair of IEMs is going to work for you. Some people hate the way the Shure's fit flush to the ear or the way the cable loops over the ear, or indeed the sound isolating tip - it works for me though, I like the feel, and having it over the ear prevents cable rustle. My wife on the other hand can't stand the pair I gave her, prefers regular buds that hang and fit more loosely, she also didn't like being cut off from her surroundings.