Some stoves incorporate a mechanical agitation or stirring device directly in the firepot. This is considered a consumable part and with enough burn time will deteriorate to the point of needing replacement. This design also seems more susceptible to clinker formation than designs not using such a device. As discussed in the corn burning tips section of this website the clinker concern can be addressed with the use of crushed oyster shells mixed with the corn.
Several stove manufactures now incorporate a burner design that eliminates the need for such mechanical stirring devices. This design seems to be working well for corn fuel customers we have gotten feedback from. The important point here is to become informed consumers, ask questions of your dealer and seek out owners of stoves you are considering. Find what they like or dislike and if they would purchase the same unit again. Most of the people we know are very willing to share this information if asked.