My experience is limited to only mixed city and highway driving, but my experience with them was great. A lot of 996, 997, and Cayenne owners got good tread life on them with mixed city, highway, and track use.
The general consensus among the 996 community is that the V12s will be good for a season of driving (mixed use) and when they start to go, they go hard and fast. They leave a good initial impression, but they are a budget performance tire, so you get what you pay for. I cannot emphasize that enough and could not, and will not, recommend the Hankook Ventus V12s to anyone, even if I hated them.
Keep in mind, your STI is AWD in comparison to the Porsche cars, but to throw in a bunch of C4S and Cayennes into the equation for an apples to apples comparison, the MPSS do hold up well. I would run them year round, and this year was a great example because of the nice temperatures we've experienced. Just don't take them up the mountain or horse around on the streets.
Most importantly, tread life will depend on your suspension setup such as your alignment settings, ball joints, tie rods, control arms, etc. Good luck in your choice!
