We just put a brand new from PTE GT3255 on my brother's car over the weekend. It's a very nice turbo. The car pulls like a freight train down low - not a ton of difference on the highway (at comparable boost levels). It spools *slightly* and I mean very slightly slower than the stock turbo.
He doesn't have the injectors yet to turn the boost up much past stock so I'm not sure how it will be at higher boost levels yet. It definitely feels stronger in the low and midrange.
We ran into a couple of problems, though, that I wish PTE would have either warned us about or thought of how to address:
1) There's some kind of adapter plate on the center section that is drilled and tapped to accept the 90-degree brass fitting for the oil feed. The plate is held on with two bolts. PTE provided the new brass fitting, which is just like stock, and we installed it. When installed, however, you can't put the oil feed line on because one of the bolts for the adapter plate is in the way. You can't take the bolt out (and potentially replace it with something else) because it's jammed up against the bracket for the stock mounting bracket. That, in turn, is held on with 12-point (I think) headed bolts for which I don't have the right tool to remove. So I had to put a short piece of brass pipe and a union in to get the height to install the line. Now the oil feed is too tall to put the cover back on. There are probably other ways to solve this, but on a Sunday morning when you're expecting the thing to just bolt up, and you're driving the car to work the next day, you work with what you have.
2) I think, but I haven't measured it, that the inlet bell on the GT3255 is a tad longer or larger in diameter than stock. Either that or the compressor housing is just slightly different, or it mounts slightly different. Whatever it is, we have interference with the IAC connector that we didn't have before. I had to remove the bellhousing, put the MAF pipe on, and then crank the bell back down to the housing, putting extreme pressure on the IAC connector (I moved the wires out of the way at least). I gotta do something different there.
Here's a pic of the oil adapter thing:
Jim