Truer words have not been spoken today... My friend's cayman gts I could get up to 131 this past weekend and my stage 2 gti could only muster about 115 on the same straight. For me the GTI was faster around the whole course by about 2-3 seconds, but down the straight the cayman walked away. It has to be aero and power delivery since power to weight is similar overall. I'm starting to experiment with shifting around 5800-6k rpm in gear 2 and 3, then letting 4 rev out. I wish the gearing was tighter, so I may try a shorter tire next time. I like the shorter tire a lot before.
I've been on the yoko a052 for 12 sessions and they have maybe 6 more session left (max). They're crazy fast the first 6-7 laps before they overheat, but that speed comes at a price... Next set I'm looking at R888R, RS4, 615k+, or just going to a RR. All the latest 200TW have been too autox focused and they just burn up on track with any heat.
Once I use to the 2 half worn sets of RE71R's, I'll move to RS4's. You lose half a second for autocross, but they'll hold up better on track. I'm only doing 7 autocrosses and 4 track days this year, so should be able to get by with the Stones.