With higher realism you use it mostly just for setting up the torpedoes and fill in the TDC data. The thing about the 0'ed gyro angle is also displayed at the scope and uzpo stations though, the little digital number field in the middle on the right.
The map can be useful if you play with map contact updates on and get hunted by more than one DD. Then the contacts you got by hydrophone are displayed on the attack map too, which gives you an good overview of the DD's positions so you not run into one's arm's while evading another.
But I think it's not so much to do there, just switch there for the torpedo settings and switch away again
