Even the restaurant quality teflon skilets and pans can't compare to Cast Iron for its heating properties. If you think they are the same try touching a cast iron pan 10 minutes after you just cooked with it (not responsible for any burns suffered during this experement) then try touching a 18-10 grade stainless steel pan 10 minutes after cooking. Better yet just take the temp with a thermometer. 18-10 grad is the steel quality used for most restaurant quality pots pans etc even teflon coated pots and pans.
Cast Iron stays hot for a long time which is good for searing meat, or creating a good crust on cornbread. When you place a cold steak into a pan some of the heat in the pan is lost. The more heat you can keep the better your sear will be. Atleast that's what Alton Brown says and I have found this to be true with my experiences.
