Got a set of these for the rear locally.
http://www.chainreactioncycles.com/c...s/rp-prod89743
only 1 ride and they seem great, better than the out going koolstops but it should be said in their defense, they had worn quite uneven which must have been my fault when I didn't set them up again as I switched from 19mm to 24m rim wheels with my gravel set up earlier in the year.
i did adjust the front and the KS are better on the front.