My favorite is also the type VIIB, however I'm currently running a campaign in a IXD2 that started in January 43 and the immersion is awesome. Average patrol time 86 days, average number/tons of ships sunk 8/42372 and average hull integrity back to port 58%. I can tell you that in 43-44 you rarely try to attack convoys, most of the ships I sunk were alone or unescorted (happened to me twice in the Carribeans : 2 ships sailing together with no escort). Also, make sure you pack your rear tubes with lots of Falke/Zaunkönig torps !
Ooops, I think I went a little OT...
