I like mine.
On a commercial tube there is absolutely no wiggle but gets difficult to adjust LOP.
On a Mil Spec tube it wiggles a bit until you tighten the screw with supplied hex key. I like how it stays on the stock in case you need it.
Its plenty adjustable although if you wanted to move the cheek piece back or forward it would take a little bit of work to drill out the holes where you'd want it. I ordered the softer but pads for both of mine as the stock one is a bit stiff.
Ive used them on an AR 15/SLR/Modern Sporter, Dlask DAR 22 in an Axiom and Stag 10.
The knobs are really quick and hold tight for easy LOP and cheek height adjustment. The pic rail on the bottom if you want to try a monopod but you need the QD cups pressed/glued in if you want the QD. I find on an AR I don't need the cheek height so I have mine removed for now to keep it a touch lighter.
I really like them but they aren't the lightest either if you are going for a super lightweight build.