I also installed these on my car (Blox ones..) along with a new clutch and a bunch of other things. Vibrations wise, it's not that much different. Maybe a little less but i can't say for sure.. However, for some reason, it feels like the front end has sightly softer springs\dampers. Also, more importantly to me, the front end of the car is much stiffer and feels much more planted. Before, on a certain stretch of road that sinked in patches and is now very uneven, the front end creaked somewhere in the dash\firewall area as the body flexed. It doesn't anymore, indicating that the front end is stiffer. Also, i saw small scratches at the mating surfaces of the body and subframe indicating that the subframe flexed and\or shifted a bit in the course of the last 233k miles. The Collar kit will prevent that as it was FORCED into place with the impact gun. The lower ones were HARD to partially push in the subframe and impossible to completely slide on the bolts. To me, that is a completely worthwhile mod and i hesitate to say if it's my favorite suspention mod or if it's still the Progress 22mm RSB that i installed ages ago. Highly recommended mod.
Also, keep in mind that i probably have the 9th gen Si with the most miles on the clock here at a bit over 233k so my unibody is probably a bit weaker now. YMMV.
New project -> TORQUEYvic!
...gotta remember the Shoebox!! It won't be forgotten!! (08SSM GD3 Fit!)
Marto Legend! SOH6 and C*CKtails!
Le **** Bulletin FM!! Des nouvelles pas full importantes qui permettent de savoir quelques affaires pour combler une discution avec une fille en attendant de s'ammuser avec cette même fille, dans un Motel!