While I linked to Op Monsun downloads, I didn't give my take on the question of SH3 or SH4.
SH4 hast the benefit of better graphics of course, but it also has interesting operational procedures. One of these is having the crew automatically organized into watch shifts, so they rotate themselves automatically, as they should. In SH3 you have to either move them around yourself or remove the fatigue function altogether. The other advantage SH4 has in that area is the "Battle Stations" function, AKA "General Quarters". This not only puts the entire crew on duty, but also puts the best available man at each station.
On the other hand SH3 has mods that have still never been done for SH4. SH3 has mods available that put working lock gates at canal and secure harbor entrances. That's not much, but I have a hard time going through the Kiel Canal without it. GWX4 was intended to add all that and more, but was never really started, let alone finished. Also there is nothing to compare with SH3 Commander, which lets you control game parameters directly instead of digging into the game files, and adds names, crew and cargo loadouts to the reports of ships you sink. Again, for some people that's nothing, but for me it's everything. And then there's the Merchant Fleet Mod, which adds more than one hundred different merchant types to the game.
Simply put, if SH4 had the mods SH3 has I would have shelved SH3 years ago.
Actually, if SH5 had something like that I wouldn't play anything else. As it is now I'll play anything but.
