Very expensive for what you get. Limiting in the distance to mount scope. Not adjustable for height if you have a larger or smaller objective. Complicated solution to a simple problem. Not adaptable to different actions - at least the way they look to me.
Burris Sig rings w/ inserts and shimmed bases are about 1/2 the cost and allow for a variety of adjustments and heights. Much more flexible (account for differences in actions and scopes) and transferable between different actions.