Got my 2006 STI back from the shop last night. Here is what I had done:

APS header/up-pipe/heat shield
Helix downpipe
HKS Carbon Ti catback
APS 65mm CAI
Prodrive boost solenoid
Snow Performance Boost Cooler (70/30 meth and water mix)
Walbro fuel pump
Iridium one step colder plugs

I got two maps for the car: pump gas and meth. The car was tuned on a dynopack awd dyno and then fine tuned on the street. On meth, the car made 314.7 awhp and get this - 401.3 awtq. On pump gas it made 298 awhp and 351 awtq. The car is so much fun to drive, especially with the meth. Peak torque is around 3100 rpm so it pulls hard down low. I am going to bring it to the track to see what it will run, but I am not expecting super impressive numbers. But out on the street, it will be fun to play around with. It definitely doesn't die up top anymore. I did 5th gear pulls on the highway for the street tune and it hit 115 - 120 really fast. Here is a comparison graph pump vs. meth: