I have owned two Anvil 30 heads and prefer it because of its two levers, the one that operates the rail clamp and the large one that adjusts the clamping force on the ball. Both levers are easy to operate and are quicker to use than the more common clamping screws. The lever that sets the ball tension can be adjusted for maximum force in different positions; I like it to be almost fully closed. Despite the small size of the ball, it securely holds a 12-pound rifle in position even when not perfectly balanced. A feature that is unique to this head as far as I know is that it is usable with both Arca-Swiss and Picatinny rails. That alone can be a significant money saver by eliminating the need for adapters with different guns.