I'd beg to differ, due to the fact that I'm on 17's at the minute. Indeed you won't need any arch work as standard, but if you're gonna lower it more than 40mm then you will. If you pick the right wheels and have a decent suspension you won't notice a difference in ride.
Also some people say that MK2's are slower with 17's, I can see the math, but I think the difference would be negligable at best.
At the end of the day it depends on what you like my man. I can never make my mind up between these 5 spokes and my BBS!