In game terms the difference between a VIIB and VIIC are mostly in the available upgrades although each type has their vocal champions. Had I a choice I would probably skip the B and go straight to the C but to some that smacks of heresy.
I like all three types provided one patrols using the boat's strengths as each has their favourite tactical niche. Sending a VII to a IX's job (or vice-versa) is asking for trouble and frustration. II's are creatures of the coasts and shallows as you seem to have demonstrated so well, or the Black Sea...
I'm a late war GWX'er and like to take a Type VIIC snorkel boat hunting in and around the west coast of the UK in the final 10-months of the war. Just for a change though, I am going to the Gulf of the Saint Lawrence, Summer of 1944, in a Type IXC/40 (
U-1221), my first snorkel patrol in that type with the Realism and Gameplay Related Fixes applied.
Realism and Gameplay-related hardcode fixes thread
Good Hunting