I own now both of them, I am far from being an expert but I can reckon they are both worth the price: my only idea is that iEMatch is way more versatile in respect of the EarBuddy, and considering the price difference I'd go straight to the first one... though I see why some people might look for a rather "quick fix" with EarBuddy.
In my rig (Mojo and IT01) the sensations I have are that EB "sits in the middle" of the two settings from iEMatch, closer to the "ultra" one: the only difference being I sense (as written previously) a sort of light "cut" on some extent in terms of scene, or rather "air" perhaps (sorry for my bad use of proper words to describe what I sense).
The lower setting in iEMatch is very "open" and seems to almost "crack up" sound in my IT01 (maybe even too much sometimes, I'll see asap with the IT04 what the difference will be), while the Ultra setting would "recompose" it (above all in treble ares) in spite of resulting in a sound a tad "closed".
EB gives me same sensation, but adding a small "veil" which I don't get in the iEMatch.
Of course those are just my sensations, and are striclty related/affected by my rig: for sure they both allow me to gain dynamics, and the test without is a no-brainer. Yet again, I will use iEMatch on my primal setup, and keep EB just for backup and to allow a second user to take advantage of the second output from Mojo.