As fun as an RPG can be.
The gameplay is absolutely fantastic. NNW on Steroids, but not as complex. I have been playing since it came out and I about to finish with a mage character. The different paths and choices make the games re-playability stellar, if you have the time. I see little of the KOTOR battle style, but you cannot stack moves, in other words, only one move per pause, which is very minor. The skill system is awesome and it is easy to establish your character within the paramaters that you wish.
Other than some lengthy dialog, the story is what really keeps you going. Twists, turns, and surprises will keep you on your toes. Excellent dialog, and top-notch voice acting make the game all the much better. At times you feel like you are really playing the cut scenes.
I have yet to have any problems and I am running windows 7 64bit. Albeit, I do have a pretty high end system, so the I can crank all of the graphics without any isses. I have friends that are playing on older systems also with no issues. It has frozen a couple of times in random places, but nothing too anoying.
Definately worth the price of admission. Lived up to they hype for me. Everything you can hope for in a turn-based, D&D style RPG. Best since NWN1. If you want to play Baulder's gate, go and buy it on Ebay!!
One word of advice, keep the F5 (save) key as part of your battleplan and you will get less frustrated when you die.