We tested 15 grills. We found that price and performance didn't track exactly. Overall, the grills that rated highest were those that are sturdier than the others, have more features and more burners, and cook food slightly more evenly across their surface. Some grates are coated with porcelain. They can chip eventually, but you don't have to season them with oil, as you do with cast iron.
Cast iron can also take longer than other types to heat up.
Another option is stainless steel. Some grates have thin wires, while others have wide bars, which support food better. Consisting of a metal plate or bars, lava rocks, or ceramic or charcoal-like briquettes, the heating medium distributes heat and vaporizes juices, flavoring food. No particular material ensured more even heating or better-cooked food. Most grills have two independent burners or one burner with independent halves.