I play SH4 (TMO 1.9) for my US Pacific fix (which SH3 simply cannot duplicate) and I play SH3 (GWX 3.0) for my U-boat Atlantic fix (which SH4 simply cannot duplicate, UBM add-on notwithstanding). Both games have their pros and cons. Both games have their own "feel" with regard to the theatres they are supposed to represent. Get both, mod 'em up to your desired configuration and enjoy both.