I have a summit viper and i can`t remember ever having it slip on a tree, As a matter of fact i have use API stands and just about every other stand made one time or another.And the summit stands beat them all hands down! It`s easy to set up on a tree becouse of the snake cable`s that they use, no pins bolts or any thing like that! I really like mine! i can`t think of a stand that ever used that i like as well as the summit viper!