They are a good unit but I think that Marlin has put a lot more R & D in his product improving it over the years. The JP Eater is basically the same as when Chris and his partner (not Jack) designed them many years ago. Marlins and JP eater came out almost at the same time.
Living in Roseville I came real close to buying the unit from JP Eater, at the time they did not have a V-6 adapter (it was being developed) so I went with Marlin. Also for personal reason I did not go with them and I am glad, I have developed a very nice friendship with Marlin, Chris, and the Marlin crew.