I have one on a pig tripod and love it. Very smooth, no matter which way you have the tripod set the locking mechanism is always where it needs to be. The 20 degrees of movement in any direction is more than enough for my shooting needs. Locks up solid. I direct mount an accuracy international at with a chassis specific rrs mount, i like the flexibility of being able to direct mount with a picatinny rail as well.
Rrs recently removed this leveling base from the soar portion of their website due to some complaints of squeaking when panning or moving the rifle around. When i got mine i could make it squeak if i moved it really fast back and forth, it never squeaked for me under normal shooting conditions, i hit it with a little blaster dry lube and now i cant make it squeak at all.
Highly recommended.