If I had to choose between more letters (extra manual) or more code (extra features) I would definately choose more features.
There are zillion very good books about the submarine war in the Pacific. No need for the devs to do that all over.
An extensive manual would be nice, especially for new comers. But for me personally I want lines of code. Books & maps I can buy in the bookstore or find on the web.
Just buy the standard work about the US sub war (writting by Th. Roscoa), then you have all you want. Maps, text, tactics, vessels, events, nations, leaders, weapons, combat, doctrine, organization, strategy...... etc
Title is "United States Submarine Operations in World War II". New you can get it for 40$ and second hand for as litle as 10$, that leaves 65 $ for a subsim with extra lines of code
