The benefit of the hexagonal plates is that spread load over a rather large circular area. Great for large cameras. I eve got a rare hex-version consisting of a large (anf heavy) square plate. I use that under wooden field cameras. It reduces the load on the screws in the wood, a protects the wood at mounting on the receptacle.Thought #2: I tried the Manfrotto hex plates and thought they were clumsy, crude, heavy, and bulky on the bottom of my cameras.
For small cameras as 35mm SLRs the small rectangular 323 plates are the better solution.