GWX 2.0 100% no map contact update, DID
I make everything on my own, 1WO is on my boat for learning not for teaching me how to torpedoe ships!!!
For me the most important thing is to stay alive as 50 families are waiting for us at Wilhelmshaven.
The second is that when you play 100% you can't tell: "ok i aim the ammo bunker or the boiler room and with one torp i'll sink this 10.000 tons ship", because accuracy is more difficult (especially in bad weather) so you will be more likely to spread 3 torpedoes on big targets and hope for impacts. Tonnage will fall down and unrealistic +100.000 tons patrols will stop.
I also use deckgun only for the 'coup de grāce' for ships>2000 tons.
Having fun is the most important thing whatever the percentage is!