You mean Summit Bucksteps? Yes I have used both. You can buy extra LW sticks individually. My opinions follows:

Summit Bucksteps
Easy installation
Good footing area, but your feet are on top of each other throwing balance off(at least mine).

Lone Wolf Climbing Sticks
Easy installation
Steps are staggered and each step can be individually rotated right or left.
V-brackets can move freely which helps on leaning or crooked trees.
Only thing LW could do to improve sticks is to give the steps a little more distance between tree, so more of your foot is contacting the step.

I easily prefer the Lone Wolf sticks over the Summit Bucksteps,but if it wasn't so tiring installing/removing screwin steps each time and allowed on public land...........I'd use my Cranford Ezy Climb rod steps all of the time.