http://www.subsim.com/radioroom/down...do=file&id=997
It makes the environment more natural, and comes with radically different user interface compared to stock. Most important is the more realistic function of the range-measurement of the attack periscope, with built in AOB measurement. No more guesstimating. And it has the angle solver side of the attack disk.
[EDIT] I used to have alot of files on my filefront page (link below), but those numbnuts deleted most of it again without telling me. Get the tutorial video about the OLC gui while you still can.