Jim prefer's GT2X to GTRS, he says its a night mare to fit. And with the intake restrictor on he could could only get 315BHP, and with the large intake pipe it is much bigger but struggles to clear the bell housing, and gear selector cables.
My mate was with me yesterday and was enquiring about GTRS for his corrado, but Jim didn't really wanted to sell it to him, he says GT2X is a better turbo.
Mine is running 1.3 BAR which it holds to the redline no bother.
I highly recommend this kit, its very very good.