Does it make any difference? Gas or Charcoal? I heard a story on NPR from a guy that write The Science of Cooking (sorry I don't recall the author's name) and he was certain that charcoal was best.
That is an argument of the ages. I suppose charcoal probably imparts more flavor that gas as it is smokier. However, there are many that swear by cooking with wood over gas or charcoal.
What it is for me, I cook on the grill all the time and having to wait and deal with all the mess that is part of charcoal or wood cooking is really not a plus. Gas is by far the most convenient.
Jeff, that sauce really sounds interesting. Did you create it? The vinegar brings Adobo to mind, yet you use tomatoes, mustard, cayenne and sugar in it which has my curiosity going. Definitely a nice mix of flavors and heat.
I can't say I created it from scratch. An aunt of mine has a similar recipe, I just took it to new places.

I think that's the way with most recipes.