My opinion, yes it is, so long as you have at least v1.4, or better still, version 1.5 "Gold". The original release of SH4, which I pre-ordered back in early 2007, and did not receive until well after it was available in stores (but that's another boring story), was like v1.0.2 or something along those lines. It was basically unplayable, maybe even worse than SH5 was, but there was an update out almost immediately... which fixed two things and broke five... This trend continued through v1.3, which was the most common form of the disk-based game for a good while. Then the v1.4 update came along, and it actually fixed more than it broke, and included "dynamic loading" of the game, to where it would only load the parts the game needed to run. The v1.5 being the last version, included a crippled SoWesPac and Indian Ocean German campaign in a Type IX-D2 boat.
SH3 with all of its updates to v1.4b is also good, but the SH4 game has prettier graphics. Some will argue that SH3 has better gameplay, and feels more "claustrophobic". More like you are on a submarine. But either of these two in Stock trim are better than SH5 in its Stock version. If you want good gameplay and German U-Boats, do SH3. If you want good gameplay and the Pacific theatre with US Fleetboats, do SH4 v1.5 (aka: "Gold"). Both of the games have excellent mods available. If you want "pretty" graphics and limited moddability with a German Type VIIC U-Boat, do SH5, but with the TWoS mod. Stock SH5 is very frustrating...
