Movie Theater 3D gives me as much of a headache as any active 3DTV (which I own). The Flickering of the active set does not bother me. 3D in general gives me a massive headache. Active and passive each has their strengths and weaknesses. If you have not actually seen active 3D vs passive 3D, you don't have any idea which is better. Kudos to LG for their incredible marketing job on passive.
TLDR: Real 3D gives me a headache, Fake 3D is worse.