welcome to the club...
many players like you was stunned by AOD, me too. of course everyone thought "wow, SH3 must kick @ss and its surely super-real!"
to make it short, its not. in stock SH3 you have no:
- wolfpacks
- harbortraffic (one little fisherboat dont counts...)
- useful communications between Bdu and you
but you have:
- many bugs
- more bugs
and much more...
but dont worry, there are severeal great mods out there which try to bring as much as possible to this game. now there is MUCH harbor traffic, a real living world, allied subs (but they cant attack etc.), more ships, a mega bunch of REAL messages (from the war era) bugfixes etc. etc. etc.
so just pick up what you need and have fun