Hesitating : Stainless steel grill vs cast iron?
I don't have any experience with cast iron grill grates, if that is what you are referring to. What I have seen at the big box stored are grates that are rather rough and thin or porcelain coated. And the grills are on the low end of the budget. Rust and chipping come to mind. My Ducane (by Twin Eagles) has solid SS rods. Here is a link where the merits of both have been discussed before. Hopefully it helps.