I recently purchased the OBD II to USB cable from Sensolutions.ca (to download and upload files to the ECU). I also bought the MTH Tuner upgrade from MTH-USA.com, it includes the utility called Cartune.exe to do the up/download. However, I haven't yet done the download, so I can't really say how good this upgrade will be for my MINI Cooper, though MTH claims about 20 hp increase for the Cooper and about 30 hp for the Cooper S. I'm waiting right now to change my fuel to a higher grade octane then I'll run the vehicle for a short time to let the ECU aclimatize itself to the higher octane (not sure if this is necessary, but it can't hurt, I just a wait a little longer). After this, and after I do my first MTH upgrade, then I'll add my new air intake and ignition components.
The nice thing about MTH is that you do not need to ship your ECU anywhere. This means no downtime for your MINI. You also get 12 months of free upgrades to the ECU programming so you can
mod your car and then get some updates from MTH.
If anyone in the Vancouver area (BC, Canada) would like to borrow my cable to do the down/upload I'd be happy to help out.
David