I finished NWN, and still have it installed, so I didn't completely despise the game.
I was disappointed by the graphics, 3D or not. The tilesets were too generic, and it just isn't much to look at. Those weird ramps for walking up hills and the trees gave it a very Lego look. It looked like a Warhammer table.
There was no sense of discovery and exploration because every environment looked and worked the same. Basically, you just click on someone in genertic Village A, and keep hitting the "1" key until you have an option for "I accept" and the read your journal to find where generic dungeon B is, and go kill generic monster X.
I wasn't thrilled by the multi-player because, firstly, 90% of online gamers are complete jerks. And second, all the maps have the same drawbacks as the single player campaign. The tilesets are usually the same; the corridors are still nice right-angles; the hills still have ramps. The only difference is the name of the tavern you start in and the name of the Ranger that tells you go kill generic orc X in generic dungeon C. Naturally, there's a generic dragon Y in there too. Ho hum.
I liked the interface. I liked Aribeth-- those are some great textures on those polygons-- but overall the game was mediocre. I think I was hoping for a game that looked like Dungeon Siege, and had the depth of BG2.