I also heard about half of the people who did the ST group buy got screwed. There's a guy on here with a sig, speedtuning FAIL.

 

So i very recently had my 2001 1.8tqm chipped through APR (the fully loaded October deal), and i could not be more pleased. It drives so much better than stock, and i get the same gas mileage (unless you foot it all the time, heh).
So, i would recommend the APR through personal experience - especially if you are getting the fully loaded ECU for base price, the ignition kill switch is a very cool option.
People around here seems to like GIAC better - but i think they are all pretty much the same (unless you are getting a KO4 later, then go GIAC).