I ran in a pair of MT20s which are almost identical but the uppers are more mesh.  Those are great for summer running where the MO10s have a more durable and sealed upper, which is helpful in the winter and does not get torn up by rocks as much.
One minor downside is that the soles are not completely covered by rubber.  I ran through the woods and stepped on a hidden piece of metal in the leaves and it went right through my shoe and into my foot.  Other than that I have no real complaints.