You aren't going to easily cut through sweet potatoes I'll say that. You need to cut them in half to have as flat surface to apply pressure to. Sometimes need to trim the potatoes to fit. Maybe 1/3 presses through easily but after that you need a hammering motion to finish the cut. You definitely need to hold the base down. It makes my life easier processing sweet potatoes. I don't use it for much else, yams maybe. Same story though.