I have found that my shoe sweet spot usually has a 4mm drop, so I thought I would try the Kiger out. The upper is a soft mesh, I can’t imagine that they would save my toes from an accidental rock kick, but as long as I watch my toes, they feel very comfortable. The one negative I did notice about the upper of these shoes was the tongue. Its attached to the medial side of the shoe, and wraps around the top of the foot, but is not attached to the lateral part of the upper which seemed to leave a bit of a gap just under the outside of my laces which allowed some tiny rocks into the shoe.
The tread was surprisingly sticky on both large flat rocks, and on roots and sand. I took them up Hanging Rock in Danbury NC, and they performed quite well. I never know how sticky shoes will be on the wide slick type of rocks going up hill, but they seemed to stick and after a few time of being careful of my footing, I relaxed and stopped worrying about slipping backwards.
While these shoes are soft and flexible, and very comfortable for a 4 mile run up and down a mountain, I think running further on a more rugged trail, my feet would get pretty beat up.
Overall I think these shoes would be fast racing shoes for shorter distances. I will not be running Grindstone in them, however, they will be kept in my rotation for tempo running.