What spec Mk4, 150 or 180bhp?
Autocar did a test last year between mk1, mk2 8v, mk3 16v and mk4 anni (180bhp) and pitted them against one another on a track.
The anni was the fastest of the day, lapped the circuit (i forget which one) approximately 2 seconds quicker than the Mk3, which was second quickest.
Hope that helps...