Like StraightSix was saying earlier, Ground Controls are just an adjustable height spring system. The spring rates and the dampers that they're matched to have much more to do with ride quality and handling than the brand of the sleeves.

**Just an example** If you bought second-hand Ground Controls with higher than standard spring rates and installed them on worn-out factory shocks, I would bet you'd be unhappy with the ride and think that Ground Controls are terrible. If you were to then replace that whole setup with Teins, it would seem that they're a great improvement.