For me a IX as early as possible....Especially the first times on the U.S. coast rockz (if you´re playing with GWX installed)....
And switch back later in the war to a VII maybe would be a good decision....cause the dive time is faster if a bird comes out of the clouds :-p
But I stay nearly the whole war with the Typ IX boat....maybe if enough renown then the last year of war in Bergen and try to get the XXI....In my first career with GWX I got it...survived all years with the IX B / C / DX2.....sunk over 1200000 tons and was depthcarged to death in march 45 with the XXI in the first mission with that boat west of scapa flow *lol*...Maybe I will survive the last year with the IX DX2 too...I will see it (or feel)
