The MTL Long Sky 2 Matryx is Merrell's mountain race shoe, and it runs like one. A 24 mm heel and a 4 mm drop put you close to the ground, 5 mm Vibram Megagrip lugs hold on steep dirt, and the Matryx upper is woven with Kevlar so it survives the rock scrapes that shred ordinary mesh.
It suits you if you race short and steep, or train on technical single-track and want to feel what you are standing on. At about 235 g it more or less disappears once it is laced.
It is not a long-day shoe for most runners. There is very little foam between you and the trail, and an hour of gravel road in these will remind you of that.