Since I've yet to play the game, I don't have an actual opinion on which review is more accurate in terms of my tastes. However, I just found it funny that the gamespot review and the IGN review had scores that were so far apart. Say what you will about the KOTOR series, but generally the main review sites all rated it within 2 to 6 points of each other (ie. 8.5 to 9.1), making the reviews seem accurate.
The fact that there is a wopping 15 points between gamespot and IGN, and 14 points between IGN and 1up is a bit curious. Perhaps my "rating" scale differs from theirs, but when someone gives the game a 9.9, then that infers it's as close to perfect as a game can get. And from what I've seen, most games that score that or near that, generally garner those same scores across all review sites (for instance, GTA:SA has high scores across most gaming sites).
Yes, different tastes and all that, but I just find the difference in ratings rather puzzling.