Mk3 was a 16v.
And unless you've driven on a cicruit whose corners get progressively faster as the lap wears on, you will need to use the brakes at some point. Fact is, Mk3 brakes are better, which allow you to brake later and harder (even moreso on Mk4) allowing you to carry more speed up to the bend. Brakes will affect your lap time as much as power, my friend.
Like I said, this was an independant test that was done. Its not heresay or opinion, its fact.