I have a TCP exhaust for my S4. It didn't sit right, the brace is crooked and there was some bending of pipe to get both exhaust tips to be the same length. But it was still cheaper than buying the non-rep version, even with labour involved. But, your mileage may vary!
I'm of the opinion that there are only a few 'original' 'high-end' exhausts out there for any given car - even the much-worshipped PHAT dump pipe is based off another design, and modified to suit.