My husband built a gravity feeder out of pvc parts from Lowes. Basically, a 3 inch diameter, 2 ft long section of foam core pvc with a cap at the top. AT the bottom is a capped off elbow section with an oval cut out of it. It works fantastically. when they ate out of a tray/trough, they would stand in the food, poop in the food, scratch food out of the tray and make it go everywhere....Now I see no ground waste. As for overeating, I can't say. They are young and growing, so as with my 12 yo son, I let them eat as much as they want! I think, as a busy mom, anything that makes taking care of the pets easier is a good thing. Good luck with your decision.