WG IV is a somewhat more original game, with more interesting non-combat encounters, but rather variable level design and wildly fluctuating combat difficulty.
The main issue with Wizardry Gaiden 4 is that the game starts you with 3 large dungeons available, and you need to complete all 3. The problem is that, once you complete one of them, you still have to complete the other 2, and the monster difficulty starts over, so the enemies never have a chance to get strong until later in the game. (One exception is if you decide to attack NPCs; these fights can be challenging, but are certainly winnable, and often winning these fights is one way to complete these quests.)
After you complete the first 3 dungeons, the game then throws you into another dungeon that starts with weak enemies, though at least this time the enemies get rather strong when you go to the deeper floors. Also, the first 4 floors of this dungeon might look familiar, except for one nasty trap. (By the way, this dungeon allows you to MALOR to places you haven't yet mapped, unlike the rest of the game.) The following dungeon has no new enemies, and feels a bit easy in comparison to what came right before. Then there's the post-game dungeon, as well. (I also note that the NPC interaction that was prevalent in the first 3 dungeons is lacking here.)
Also, it's a bit odd having the Rod of Resurrection being the strongest available weapon, and with Priests getting an extra attack at level 1, Priests end up being one of the better physical attackers until later.
Final warning about Wizardry Gaiden 4: DO NOT CAST THE SPELL THAT'S SUPPOSED TO REMOVE CURSED ITEMS. It will work, but it will also corrupt your save, and you really don't want that.
Wizardry DIMGUIL, on the PlayStation, feels better balanced, though it lacks the WRPG element of NPC interaction that Wizardry Gaiden 4 has. It also has no translation patch to my knowledge, but the one major language dependent puzzle is actually in English for some reason.
By the way, I really do recommend Elminage Gothic. It sticks to the classic formula, but does many things really well, like how enemies are designed to give every class a chance to shine. With that said, things can get a little unfair; the final floors of optional (parts of) dungeons tend to have rather dangerous enemies for that point in the game, and the final post-game dungeon can get downright unfair. (As in, there's a couple enemy types that could wipe out even a party with levels in the hundreds, which the game actually expects you to reach (and which the dungeon is designed to take you to).)