I bought these for trail running.
-great traction, even on downhill on with loose surface
-light and breathable
-run about 1/2 size too small
-tends to squeeze the toes together(perhaps would not have been an issue in larger size)
-Boa system can be adjusted in small increments to tighten it, but to release tension you have to release it almost all the way
-the sole has soft areas so if you step on small rock just right it digs into the foot quite noticeably