Nice Horrra.. . Looks like they are wearing well. I have heard nothing bad about Metzeler tyres.. I used the K2 on the 675 and they were brilliant on the track and the twisties.. Quite terrible in the wet though. But, thats not really what they were designed for..
I borrowed a BMW K1200R for a weekend with M5's on it. Felt very sticky and filled me with confidence in the corners even with all that torque. I think they are a great tyre. I would be keen to see the life that you get out of them especially with the track days.
I used to get 3 track days and some communting out of the K2's.. And they felt great until the end.