I have this setup. I bought it for three reasons:
The first hasn't been tested. The second is absolutely great. It sounds like a sports car...not a car with a muffler thrown on. It's a great sound, one that doesn't kill the boxer whirr but makes the car sound great.
I guess my headers muffle the car, because it is much less noisy than my old 5Zigen catback.
Basically...the whole system is 2" and it's matched. That's what brings me to my 3rd point...it's as close as you're going to get to a complete system with the POS stock cats on there.
My only issue has been with the flanges. They don't seem to fit properly. I'm using electrical tape, but if you go out and thrash your car around like I do, the hangers will slide back and forth and one of them may slip out. The system won't go anywhere-it'll just hang "tilted." Very ghetto.
Don't know how to remedy this yet...maybe some clamps...