We have used one of the cast iron camp grilles (flat on one side and a corrugated texture) through the years on several differnt types of gas stoves. We have upped the BTU output on stoves several times, and so far the "well seasoned" cast iron grill has given a fairly even distrubution of heat. My wife has started using it on one side (2 burners) of an indoor Jenn-Air grille with the stove and it satisfies the even heating requirement again. Don't know about the thinner plate steel ones, thinking the cast iron does well as it does for cast iron skillets, dutch ovens, etc.
Can't beat well seasoned cast iron in my opinion!