I can't give you any first hand info but I did buy a set to install on my Donzi Blackhawk to put a little hook in the hull. But I sold the boat before I got to install them and sold the rocker plates after.
But, I did talk to a couple people that used them and they had nothing but good things to say about them. They said the boat could run faster in the sloppy/rough water because the rocker plates were part of the running surface as opposed to K-Planes that "drag" in the water. Made sense to me!