I normally get the XXI when doing a late/almost end war campaing. Normally try to get it March/April 45 and do a little rpg, in being the first to get one operational and do one or more patrols with it.
But no surface, after exiting the fiords, it is like a true sub, always submerge.
Did have some fun in attacking destroyers with the acoustic torpedoes and evading the rest with the fast speeds.
I think it is up to you and what do you want to do with the game. More real life simulation/emulation; rpg or just play a game and have fun. Have a type XXI in 44 and try to win or sink everything and show that you have a uber sub.
