I have a Calculated Kinetics on my OSP 3" Micro and C&H on my 4.7" PRO.  Both were mounted using the plate-manufacturer supplied fasteners to the torque specs provided (no spec is given with the C&H).  The CK sits higher and has worked loose twice. I finally gave up on the torque spec and HULK torqued it.  It has stayed tight since.  Ran the first 220 rounds through the C&H / PRO today and it stayed tight.

Based upon this extremely limited experience I would opt for the C&H plates.  In fact, I will be changing the plate on my 3" OSP eventually. I already bought the C&H but don't want to waste ammo changing it until the CK loosens again.  If it stays tight I guess I'll need to pick up another Hellcat since I have a spare plate (ARFCOM tradition).