Well I've got over 12,500 miles on the K60 that is currently on the bike. It is pretty much toast at this point. I could probably squeeze another 1000 out of it if I was desperate, but I'm not. So I'll be sticking the new K60 scout that is sitting in the garage on there this weekend. For those that might care I'm using 140s (recommended if you are looking for dirt). I have read the complaints about the new center strip, I'm not all that convinced about it being so much worse than the original style (I'd still go for an original style K60 if available). My reasoning is this, by the time the tire has worn to the center strip I think it will have worn flat enough that on a softer surface the rest of the center blocks should get traction.