I use this foot along with RRS LCF-50B swapping between the two. The CP-51 primary advantage is lower profile which provides better balance mounted to a ball head, but more importantly allows proper balance on a compact gimbal like the jobu Jr3. Mounted in the Jr3, the CG is below the pivot point which allows the setup to return to level when you let go. With the RRS foot the lens is slightly top heavy and tends to drop forward of aft unless you apply some drag. The RRS foot works with light drag applied, but the CP-51 has the edge here. As a handle, I can grip it comfortable with bare hands, but with thin gloves, the gap is marginally too small. The RRS is much better here with gloves and a bit more comfortable overall in handling. When shooting handheld, the CP-51 foot resting on the palm of my left hand is much more comfortable as the RRS foot has cutouts that irritate after some time. Both feet are well made with the RRS being slightly longer. Both fit my RRS lever clamp...