I have realism at 97% but I miss the external view. On my second "career" (which is going nowhere) I have external view enabled and I like to set the camera on the bridge of ships and watch the torpedoes approach. I never use the camera to target, it seems really hard. I get lost using it all the time and have to recycle through an internal view to get my bearings
Come to think of it, I don't know what I have left off and don't use 100% realism. Something annoying no doubt.