What can i say... in example, in SH3, i use only type IX, i only use Type VII if i am enforced but i change it as soon as posible, and always refuse the type XXI.
Type II is in my opinion a coastal patrol sub, so i dont start a campaing where i am enforced to use it.
I am a IX lover....
Looking my personal choices, i want few subs, but with better quality.
Just a personal opinion.... nothing more.