My tuning is almost complete at this point. I gotta say, this X37 has made an incredible difference and I am extremely happy with my purchase. I am not posting vdynos or anything yet, but we are talking about about a 40-50% power increase from 5K up vs the Cobb OTS 3 map. Even in the lower RPM's there is a signifcant power boost that is very, very noticeable. This is with 98F ambient temperatures during the tuning process, which is pretty brutal. (the Depo IC has performed remarkably well, I must say. Haven't gone over 105 charge temp)
I also have, by the standards of this forum, minimal modifications done to my car and I'm still getting an incredible performance boost. My previous car was an LS1 Camaro manual transmission with full bolt-ons and an e-tune, and I think this little Fiesta might actually be faster. It's hard to tell exactly, because it doesn't have the primal V8 roar that my Camaro did, but I go WOT and then next thing I know I'm approaching 90 and going oh shit! 2nd gear now feels like a literal rocketship (if I hook up), and 3rd gear just pulls without hesitation all the way up to redline in the blink of an eye.
I also want to point out that the easy daily drivability of the vehicle has not been sacrificed. The feel of the car, in regards to throttle response and that instant spool of the original turbo, it feels almost like it did stock. Which is what I wanted, I did not want to sacrifice that by going to a "big turbo".
Very satisfied customer here.