We do all smoking right now, because 1. I love it, 2. it allows me to handle other duties while the meat is smoking. 3. most importantly, we are a BBQ company, and it is the reason people get in our line.
Last year I was at an event where the guy across from me had all his smokers running, but was also grilling some ribeye steak sandwiches and corn on the cob. I chatted with him about it and he was the only one at the even selling steak sandwiches, it gave him something unique to sell and he did better than I did on total sales that day.
I have a couple events we may consider it for this year. We do a rodeo and a couple street festivals that I think ribeye sandwiches would go well at. So I may add it. It does add another person manning the grill though.
I'd be interested in hearing what other do as well.