I just got the game yesterday, and I have only been able to play it for an hour or so. Still, my initial impressions are good. I've played Baldur's Gate, Planescape:Torment, and Icewind Dale II, so the controls are familiar and easy to use. That's one of the main things that kept me from enjoying Pool of Radience--the controls sucked.
The artwork on the character sketches and the landscapes are beautiful as always. As to the rules, judging by the accompanying rulebook, it almost appears as if they were able to implement more of the 3E rules than NWN did. The experience and class progression tables go to level 30. And the AI seems to be fairly sophisticated. For instance, I picked one of the pre-generated parties so I could get started quickly, and the leader of the group is a Drow Priestess of Selune (I know, wierd, huh?), and the people you talk to actually kept bringing that up, and were worried that they couldn't trust her because she was a Drow. I know that's not a hard thing to program into the game, but it shows that the designers were thinking of details.
I got a bonus disk with the game, but I'll admit, I was so anxious to get to the game that I haven't checked it out yet. I don't know if it's an expansion on to the game, or a soundtrack CD, or a character editor, or new images and sounds for the characters, or what. I'll check that out this evening.
The mini-quests and storylines appear pretty standard for these games. If you liked them in other Black Isle games, you'll like them in this one, too.
I do like the fact that they included a few races with higher ECL's, like Drow and Grey Dwarves.
All in all, I like it so far. I'll try to expand on this review in a few days, after I've had more of a chance to play the game.