Yup, the GTO Fourm guys seem to be real good. I've been a member over there almost as long as it's been a site. I don't post much, but I usually follow along to stay in the loop. The LS1GTO site has some great resources and stuff, don't have an account there, but from what I've read, still decent people, just more of them, which usually means more spoiled apples.
If I had gotten my GTO, it woulda been the 350HP one, not the 400HP one. I've only driven the newer one a few times, and it was a brusier, I loved it.