well, I can say that the GT3037 and the Garrett 0.63 rear housing is like a f**ken hooker on speed.
full boost at 4100rpm (20psi) and makes 310rwkw before the back pressure starts to show its ugly head.
oh, and its not laggy..... Between the 2871 48trim and this one, I'd say the difference under 3,000rpm is barely noticable. Driven 2 x R33s with these setups, and Dale_FZ1 is just waiting to drive my car to confirm this.
Don't worry dale, I'll get down there sometime soon I hope