Are you really shooting at 11mm very often? I guess it could make sense for music videos, but I'm having trouble thinking of many narrative applications.
Hell yes. Whenever I can use it I do so. I am obsessed with distorted hyper-wide and well-composed imagery, even more so when it's moving. The surreal quality is something I really love.
I also like to do scenery, just for myself, in 4K @ the 11mm end. Sometimes forcing foreground objects against sky shots, like a foot on the beach. And I'll literally just sit there and watch it on my 42" 1080 Samsung LCD. S'like being there, man.
I want to try the 18-200. Doesn't that lens have a VR function? Seriously would be killer for handheld application.