Hey mate I have a hi flow on mine but I have a VG30 rear housing (so it will be laggier then yours), 1st gear I dont really get much boost at all unless I launch the car from about 4 - 5k 2nd gear it comes on strong from about 4500 and really throws you back around 5 - 5500rpm.
It is a LOT laggier then the standard turbo but now that im used to driving it and knowing how to hold my revs etc it doesnt seem so bad at all.
My supporting mods are : Power FC, GTR Injectors, GTR front mount, 3inch turbo back exhaust, and a bosch 040
any other questions you have feel free to ask me and ill try my best to help
PS I made spot on 200rwkw with 17psi