The visual system comfort in virtual cinemas in VR should be a best case scenario (once the resolution becomes adequate.) There's a few big missing pieces in current VR - no accommodation support (resulting in vergence-accommodation conflict the closer something is), geometric/perspective distortion due to the unaccounted for translation of the eye relative to the screen. In a virtual cinema you're focused on a fixed, distant plane that tends to remain centered in your view, so once the resolution improves I suspect the cinema experience will be the most natural feeling/looking thing you can do in VR.