I bought a pair of these for running before I saw the thread; they arrive tomorrow (according to UPS tracking). From all the reviews I have read, they hurt like the dickens until all the usually-not-used muscles and such in your feet strengthen up over the course of a few weeks. THEN you get to enjoy the benefits (faster runs and sprints, significant drop in running/ walking related injuries, etc...).
Honestly, I never really thought to much about using these for paintball, I have a nice pair of USMC issue combat boots that have several hundred miles on them, so they fit all nice and perfect

. Running in those beasts is an ENTIRELY different story though... But maybe after my poor widdle feetsies get used to the KSO's I'll try a few rounds with them and see how they work.