re: Anyone use Smoker boxes on gas grill?

I have a Weber Summit with a dedicated 5th burner for the built in smoker box. While it's bigger than most of those after market boxes, it only holds a couple of cups of chips/chunks. It works well, but you do have reload it occasionally.

It is not as good as a dedicated smoker for long smokes, but it is great if you just want to add some smoke flavor to grilled dishes that you are cooking slowly. I use it for chicken quite frequently.