Finally got round to flashing my car today (JHM 91 octane tune).. I did it myself over JHM's VPN in the states. Pretty easy to do although I did have problems earlier in the week with JHM's own browser but the process is simple.
I can't compare it to any other tune/remaps out there but I went with this one after reading up on all the positive feedback on the American sites and also a friend local to me had already done it and said it was impressive.
I can't say I'm disappointed, it's a fair kick in the nuts as soon as you touch the throttle. Very responsive and noticeably pulls harder. It also got rid of my CEL (I have no cats) and has removed the speed limiter. All for £380. I should add.. you need to buy a cable (OBD2 to USB) from JHM but I was lucky to borrow my mate's one.
Next thing will be a dyno just to see what the difference is.
My set up is 2.5" catless DP's, non res Miltek, BMC filter and the tune (sorry remap, it's an American thing!)