I am thinking about purchasing the ac schnitzer exhaust for the E53 X5. I have done a vast amount of searching in forums and the internet and have not been able to find much on this. I know its around $2600 new but cant even get some nice images of the dam thing. Anyone here have one on their X? How does it sound? Any significant performance increase? How does it compare to Remus/Dinan/Eisenmann?