A good game with some technical issues that keep it from greatness.
With this said though, the story of NWN2 is quite basic as far as role playing-fantasy games are concerned and on top of this it is a rather long game (30 to 50 hours depending on if you know what you are doing). Because it is so long and the story so generic, the game may become dull after awhile unless you are good at finishing long games. If it is any consolation, later chapters are far more interesting than early ones, which are primarily concerned with your character trying to figure out what the heck is going on. These issues are easy to overlook though due to the general enjoyment you will experience from developing your character into his/her most powerful state.
However, there are three major issues in NWN2 that hold it back from being a truly great game. The first of these is that the camera is often frustrating and unable to show corners adequately. The second issue is that there are a few bugs and glitches in the game that, while not crippling, are a nuisance and can be challenging to work around. The third, and worst, of these though is a mediocre AI system. AIs will walk right through traps that are plainly visible, ranged characters will charge right into battle, spell casters won't cast spells, and everyone will guzzle potions like they were water. Now you can work around this by micromanaging your party, but this becomes increasingly demanding as your abilities mature.
Overall, despite a few lack lust technical issues, the game is worth playing even if it's just for the sake of saying you did. Whether you finish it though is up to you…