How are they for fade and wear?
Also, can you shed some light on the exhausts that are available for the MK4? Turbo-back, cat-back, sport etc... totally lost on that one 
I don't drive the car hard enough for a long period to feel any fade.
The standard downpipe is extremely restrictive so it's common for people to upgrade it, if you know a friendly MOT tester then a decat is the way forwards, if not a decent sports cat.
As for catback systems - there are loads of aftermarket one available, I'm running a 2.5" Milltek with a 3" downpipe/decat and I love it.