Don’t go by the reviews of the people who don’t know how to take care of cast iron. You have to season them before first use. I also spray them with a kitchen pump oil sprayer.
You have to keep them oiled and then they won’t rust. Especially if you have a long cook time the heat burns out the oil. Also if you don’t plan on using it for a few months make sure to oil it.

Food tastes better than any propane grill I’ve ever used because of the cast iron.