We had a TT STS Vette in our shop. It was ok. It took forever to spool and while my boss was driving it the scavange pump blew a fuse. The didnt notice the huge cloud of smoke behind them until it was to late. COOKED BOTH THE TURBOS. Also with STS, I was not impressed with the fit and finish. Especially the tail pipes. Looked Terrible. I would go with the manifold mounted turbos. Much more heat energy is used and I personally think you get more bang for your buck.
I'm just a noob, but I remember seeing a tuner shootout in Motor Trend not too long ago titled, "Strike Force". I was really diggin the blue GTO by MTI with a 422(?) cu.in. and STS in the back. Went 193 mph in the standing mile, described as "uneventful" (which i think means "good" when you're going that fast.) Although I cannot answer for the oil control problems and quality issues. http://www.motortrend.com/multimedia...arison_videos/