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I think Boomer works for the company, wish he would just come out and say it. It's like reading a phony Amazon review.
They should function very similarly to aluminum GrillGrates (got on a Groupon special, WooHoo). The purpose is basically the same, flare-up protection, different kinds of heat than just natural convection, maybe better grill marks.
I love cast iron, but don't need it for grates really. It has a greater mass and heat capacity, so will take longer to heat up and then stay hot for longer. With an egg, we have NO problems with it staying hot, but I want to be able to cook sooner and change my temps faster.