Its an age old debate about what engine is better, the 16V performs better than the 8V on all counts and thats gospel. The reason why people like the 8V is because it doesnt have to revved to get the performance out of it, so it "feels" like its better to drive. Also a smaller engined car is more likely to be driven nearer its limits so you feel like your going faster and having more fun.
I have a 16V and when going slow it feels the same as any other golf because your not taking advantage of the increased breathing capabilities but when you bury the throttle joining a motorway on the slip road it flies, its what a 16V is about, getting on cam and smiling as you launch past everything else.
GOLF VR6 is correct when he says all golfs should run on high octane fuel to get the best out of them. The ignition can be retarded on the 8V to use low octane unleaded but the 16V cant be retarded. Both cars will respond well to K-star.
As JV rightly said the 16V will be an excellent track day tool, it will be used at the rev ranges it loves and you will enjoy the experience more. I would have a decent road car for everyday driving and get a cheap 16V purely for track days, a cheap car to mess around on, to tinker with and hone. Also its probably better as explaining to the wife why the car is written off make take some doing.