If you are still on the fence about saving valuable floor space and getting rid of those antiquated cast iron radiators, keep reading... Cast Iron The Pros Can last up to 50 years Remains hot for a long time after the system is turnoff Low price unless you are looking for a decorative model The Cons Long warm up time Very heavy Freight costs are higher Harder to install They require a very strong mounting system Bimetal Aluminum Steel Radiators The Pros Durability 20-year warranty Volume of hot water is very low Simple installation Corrosion resistant Takes up less floor space Modern look The Cons Slightly more expensive