I totally agree. I have Lensmates on my X100T and one of my X-T1's and really feel like they complete the camera. I recently snapped up a second X-T1 that I found a great deal on, and wow....I'm going to have to order another thumb rest .
The Match Technicals are great, too - I have one of those on my X-Pro1. Mine is in the form of the Fujifilm-branded "X-Pro1 Ergonomic Extension Kit" (thumb rest and soft shutter release bundle) that I found on sale for under USD100. For any X-Pro1 users looking for a thumb rest, this Ergo Extension Kit is actually a Match Technical E-7s simply boxed in a black Fuji box, also including a very nice (not Match Technical, I don't believe, but I'm not sure who makes it) soft shutter release.