I thought I'd be a VIIB person, I liked the dive time, the speed, it worked for me.
I did my first patrol with a IX, got damaged to heck because of it's slowness (1024x TC while going to/from patrol area and ran into warships, got pounded before I could dive, but survived), but I'll be damned if the thing isn't a lucky charm or something...my first patrol, ran into a
14 ship convoy, with a SINGLE V&W escort...took out the escort with gusto, then, well, then it was just like shooting fish in a barrel.
Sadly 4 of those puppies were neutral, but hey, 11 ships in a span of about 30 game hours isn't bad...
I'm somewhere in 1941, and this was somewhere west of England, not too west