Put brand new K60's on my 800 a few weeks ago and then rode a 7 day road trip around colorado to Santa Fe the long way. 85% street 15% dirt. My impression is that there was an unstable feeling at certain speeds and in the grooved roads for sure. At speeds over 90-95 (raced home for a forest fire) I think they had a bit of an unstable feeling. Other than that I think it was the tread pattern. I got used to it. I still think its a good tire, and will put them on the new bike (old bike melted down in forest fire).
2012 F800GS Trophy, F650GS
2009 KTM XCW 530