I played with a Crown Graphic for about a day or two this summer, but didn't have any film holders on hand. My roomate had a 6x7 back, so I tried it on some still shots.
What I really liked about it is that it's so light you can put it on a tripod that's designed for 35mm without risking catastrophe. I have a manfrotto with spidery legs and didn't have a problem keeping still. I wouldn't try that when it's windy, but at least I could use my existing equipment.