I made that exact switch a few years ago, and I was pleasantly surprised by how much money I ended up saving on my energy bills. Radiator systems are much more efficient at heating a space than forced-air systems, since they don't have to push air through ducts and can focus on heating the actual objects in the room. Plus, they tend to last longer than forced-air systems, so you'll save money on maintenance costs as well. You can to find one.