There have been several reports. I've had them on since mid-summer. As DD King sez they are quite a bit like the 250s, but I have not had the slipping problem. In fact, I think that they are much better than the 250s in the handling department (but then, I don't ride nearly as hard as the NGM). They do seem to have a softer compound (than the 250s) and I do not expect the milage that I got from the original 250s. I was wishing for the 250s to wear out faster, though. The Shinkos have been much less prone to wobble than the 880s. What will my next set be? Either 'stones or another set of Shinkos. BTW, a lot of folks like to claim that they are made in China, which is not true. They are produced in Korea.