Ive never tried the V4 intercooler but I have a PTE Stock location. This intercooler is awesome. Huge gain over the stocker. This I/C is huge compared to the factory piece. The only drawback I saw was how to install it. You have to remove the electric fan put the intercooler in from the top bolt it up. Then put the shroud up from the bottom and put the fan back on then. Then bolt the little pieces that surround the front sway bar. Other than that I love it.
Last year my car had stock turbo, I/C, and downpipe it ran 12.20 @ 109mph, with a stock rebuilt engine, stock heads at 22psi boost. I added a TE60 turbo, PTE Stock Loc. I/C, and a 3" downpipe and the car responded to low 11's at 119 mph. This was at 24psi boost.
I turned the boost down to 18psi, because I was thinking the turbo made the biggest difference and the car still ran 11.70's @ 114mph. I think the I/C made the biggest performance gain over my other mods. I did notice one thing though, I think the turbo spools faster now with this I/C. All I have for a stall is the orange stripe converter.
Just my $.02