I'm currently in the position of having bought a mint Mk2 8v, I really enjoy driving it and can't fault it, other than wanting more power.
The 8v pulls well from low revs up to about 5,000rpm and then runs out of steam. My 8v is in such nice condition that it deserves to be kept standard, and so at the moment I'm keeping my eyes peeled for mint low mileage 16v, but finding one in as nice a condition as my 8v will be hard!
I've never driven a 16v and keep reading conflicting reports regarding low down pulling power. However my mechanic who runs a specialist early GTI garage said that a 16v will feel more like a 1600cc engine low down in comparision to an 8v, and he works on them for a living.
I guess until I get to drive one I won't know for sure
