Corn stoves can save lots of dollars on heating costs.  With the pending large increases in natural gas and heating oil prices many rural and suburban residents are using wood, pellet, or corn stoves to supplement existing natural gas heat or replace it completely.  The major difference between the renewable fuels and natural gas is that the resident has to stoke or load the fuel in the stove where natural gas or fuel oil was continuously fed by fuel lines. Those who are away from home more than 4-8 hours may not find renewable fuel stoves of any advantage.  The loss of heat when a stove runs out of renewable fuel can not be tolerated in very cold climates.  Residents who spend little time away from home will find renewable fuels rewarding in spite of the small tasks of obtaining, storing, and loading the stove with fuel and removing ash.
There are some high standard renewable fuel stoves with larger hoppers,  thermostatic controls, and automatic starters, but they are far more expensive, and are limited to pelleted fuel.
Performance of renewable fuel stoves depend a great deal on the quality of fuel used and periodic maintainance given by the homeowner.  It is very important that the fuel be Clean, Dry, and Room Temp before loaded into the hopper.
After years of heating with wood, then wood and natural gas combination, and the last 4 years with natural gas, we have added a corn stove.  Our savings using the corn stove last year was over $200 a month. It paid for itself in one winter.