Visually stunning, immaculately constructed, but ultimately disappointing.
Blizzard has put together a visually beautiful game with five character classes with completely different builds. What wasn't clear to me at first was the complete freedom I had to build my character. I first began with the monk and after I leveled a few times, I began to agonize over whether or not I was using the right build. I didn't want to put points into a skill out of noobishness only to be unable to unlearn it later. I scoured the Internet trying to find perfect builds, but it was overwhelming. Only later did it become clear to me that one can remap a character's skills WHENEVER ONE WANTS AS OFTEN AS ONE WANTS completely without penalty. Sometimes it is necessary to come up with a particular sets of skills to take on a particular uber boss. The fact that I don't have to spend half the game offline doing research for the perfect build was a tremendous relief to me. I've never enjoyed that aspect of modern gaming.
The maps, terrain, and dungeon designs never repeat as far as I can tell throughout the game. This is a mixed blessing as I often felt compelled to explore every shadowy corner out of fear that I might miss something. The monsters are similarly varied. You'll meet different types right up to the end.
The blacksmith and jeweler provide another venue for keeping your character outfitted exceptionally well. Unwanted magic items can be disenchanted to provide the shards/essence that are required to manufacture certain equipment combinations. Those that could be useful to other classes can be stored in a universal bank accessible to all your characters to make it more convenient to twink out new characters in gear that would otherwise be out of reach for a while. The jeweler allows you to combine gems that fit into socketed equipment providing even more bonuses.
The storyline is adequate. The cinematics, at various points, are better than anything you'll ever see. I played through it and won it in a couple weeks. This unlocks Nightmare mode, which when won, unlocks Hell, which unlocks Inferno. Add that to five different character types, and clearly this is a game that could suck out your life.
I've only got one criticism, but it's a big one. The game plays best in single-player mode, in my opinion. However, it is much easier to level, to advance through the game, and to acquire more elite equipment in multiplayer mode. However, I didn't find multiplayer mode that much fun. It's run, run, run all the time, constantly struggling to keep up with your party. I found it exhausting and not much fun. I think if you were playing with people you actually knew, with with everyone miked up, or in the same room on a bank of computers so you could talk could be a lot of fun. There would be less frantic scurrying about, and you could enjoy the game together. Inevitably, when you're in a random party, you'll be led by somebody who's won the game six times already, and they just want to get through this act as soon as possible, and it will be a sprint where you'll scarcely have time to notice the game as it rushes past you.
Because the multiplayer advantage is so clear, you'll be forced to choose between enjoying the game or excelling at it. For me, that's a tough call since I want all that awesome equipment, but at the same time, I want to enjoy the process of acquiring it. It's a major flaw in an otherwise excellent game, and it's one without an easy fix. Still, this game is no slouch. You'll at least enjoy winning the single-player mode. Afterwards, you'll have to decide if continuing the game appeals to you. For me, it is a decidedly unexciting prospect.