I installed them and they worked like a champ. I am using in a garage on bare concrete. I move the bench around on a wheeled carriage frequently so i have a need to re-adjust the feet often. I did not detect in slippage on the concrete floor. I found the ability to use screw adjustment as opposed to shims to be superior and more easy to get right quickly. Prior to this, I was using wood shim wedges under the legs. The screw adjustment is much more precise and allows me to get it perfect which adds to the stability.
Bob