Got my sparkplugs, TStat, sensor and tune all done this weekend from Gearhead. I live in Canada so it was a bit of a pain to get it all here, but so worth it. Car stays nice and calm under 2500 RPM's so it can still putz around town comfortably, but holy does the boost come on at 2750 now. Over 100 kph is great, used to struggle around 180 kph but no problems now. Transmission changes are also a bonus, love the faster and more aggressive shifts. Not going to call it a "whole new car", just going to say this is exactly what the car should have been from factory.
Up next might have to be some new tires for next summer. Currently running Cooper RS3-G1's, and while they are on the performance end of all-seasons, they are hanging on for dear life. Something grippy and summer only is probably in order.