How much better (or worse) is SH4 than SH3?

[MidnightTempest]

I discovered SH3 last week, my first ever submarine combat sim and I loved it, have been playing it non-stop ever since.

Now the question is should I upgrade to SH4? Besides slightly enhanced graphics, a focus on the Pacific Theater between US and Japan, are there any major reasons I should be playing SH4 instead?

What are the primary differences and modification between the two?

Are there any "must-have" MOD out for SH4 yet? Like the GWX 3 for SH3?

Or should I stick to SH3 and wait for SH5 to come out early next year?

So many questions, I know, but thanks in advance for answering them.


*NEW QUESTIONS:

-I was disappointed that in SH3 you can only vist the command room, the radiomen, the bridge and the targeting room. I wish you could roam the entire sub at your leisure and also observe how the men in the torpedo room, engine room, etc, work, and how they interact with eachother in resting quarters. Are these features implemented in SH4?

-Has the career mode improved in SH4 over SH3 in any way?

-Are there more interactive options during the "off duty" period after each patrol to visit the towns for relaxation?



Thanks again.