There basically two supermods that alter the behavior of the submarine, RFB, and TMO. TMO also has a campaign component, while RFB relies on Run Silent, Run Deep Campaign (RSRDC). RSRDC is also available for TMO, as well as stock.
The stock campaign is abysmal.
Abysmal. Nothing about it is acceptable, IMHO. It's not the least bit realistic from a historical standpoint, and as a GAME, it's nothing if not boring. The convoys are overescorted, yet the escorts are 100% incompetent. They didn't even get Midway right (too few CVs, LOL, dunno how you mess that one up).
So IMO, RSRDC is mandatory, unless you are running TMO, in which case the TMO campaign or RSRDC is available.
RFB vs TMO is preference.
Playing stock is a bad idea, IMO, and playing the stock campaign is unforgivable.
