MCFI is awful, yes. But that's because it's really hard to interpolate frames that aren't there to begin with, not because 24 fps is somehow the ideal framerate for video.

As for me, 24 fps is incredibly noticeable, especially during panning scenes. To the point that it often takes me out of the movie; I've been wishing for higher FPS movies for years.

Of course, I'm also one of the very few people that can see phosphor decay in plasma TVs, so...