they cant be too bad if there used on a hell of a lot of Tsukuba Circuit cars - including HKS' Monster EVO, not only that, but alot of D1 cars and MSC cars as well.
havnt seen to many problems thus far, maybe its the quality people are getting which causes wear, but from my knowledge they only eventually decrease wheel bearing life.
im running 40mm's and 25mm's, will see how they go when im drifting again