These were awesome! My wife marinaded them with the Pioneer Woman skirt steak marinade (google it) an they were delicious.
Here's the recipe: http://thepioneerwoman.com/cooking/2013/03/beef-fajitas/ Hot mesquite fire cooked on the lower grate. This was the first time I cooked with the Lid Open. I wanted a good char on them and was afraid with the lid closed that they would cook too fast. It worked perfectly, about 3 minutes per side.