The car feels awesome when you drive it hard, aside from the slalom part, the DSG GTI could be close in the straight, and to make things fair a stage II would compensate the extra power of the ST over the GTI.
From the drag tests from Car and driver magazine,, a manual ST and manual GTI do the same time, 14.8. Yes they managed to do the SAME time with both car, but here the GTI has shitty all-seasons tires compared to real tires with the ST, both the ST has more power, more is heavier. The thing is that the ST has more top speed, 148 mph for the ST, and 125 mph for the GTI. So after a 1/4 miles, the ST would probably pull due to the limited top speed governor of the GTI.
So if we stick in a 1/4 miles drag straight, a stock Dsg would beat a stock ST. Then a Stage1, manual or dsg, would beat a ST.
And a stage2 GTi would destroy a stock ST, period.