We watched Dunkirk on opening day in an IMAX theatre where the sound system vibrates your seat and unless you're sitting in the back three rows it's difficult to take in the entire panorama. The only thing missing was the sprays of water like you get in the Pirates of the Caribbean theatre in Disney World. In retrospect I wish I'd watched it in a regular movie theatre as my head kept bobbing around trying to take everything in and the volume level gave me a headache. According to the reviews…