I have experience with both types, as well as stainless and chrome plated. I do like the porcelain on one of my gassers as it makes clean up fast and easy. The cast iron grates, I do not clean, but have had people express concerns for their food safety. I prefer cast iron for the effect it can have on both appearance and thermal mass in cooking, in my mind, it is a superior metal for searing meats without a doubt. For smoking, I am less inclined to declare cast iron's superiority as I prefer thermal mass to be held away from the meat for smoking, thus I use a cast iron skillet under the meat in my kettle to hold thermal mass.