I no longer use any kind of wrap when cooking on my kamado. With such little airflow compared to most cookers, I find it's not worth the effort. My ribs do turn out a touch drier, but I end up with a bark I like better, and my labor gets cut in half. If I find myself cooking on a more traditional smoker/cooker, I'm usually away from home and use what I have available, which generally means foil.
On a semi-related note, last weekend I smoked a small pork butt that I cooked in my cast iron Dutch oven, lid off. I pulled it in the Dutch oven after cooling off, so all the juices ended up right back in the meat. It was fantastic, and it made for great leftover lunches.