Did you center the upper over the diff or did you offset to account for the torque steer they say happens? Do you happen to have any pics of the installed unit?I didn't hit many events after the PM3L just due to other life events conflicting with autox schedule, but it was a significant improvement over the stock 4-link. The car handled better and was able to power out of the sweepers a lot better than before. My only real complaint about the PM3L is the added NVH due to the spherical joints in the upper link.
I do have a finished garage now with heat/air, but with talks of a baby in the near future I'm not sure how feasible this project is. I'll likely end up with a MM torque arm like many others here.
My tires are the weakest link at this point, 295 Federal RS-RR's, especially since the procharger addition. They were my track wheel/tire setup but with the current hp they're barely sufficient for street driving, so hopefully new wheels and either Re71's or A052's will be in this cars future.
My brother just got a set of Potenze RE050A's and loves them, 295's on his c4. Said they are night and day over the same size kumhos.