I played the OC either 2 or 1.5 time from beginning to end, and I'm not saying that NWN hasn't got any multiple solutions to quests, I'm saying it doesn't have more than BG2. At best it has the same number of solutions to each quest as BG2. I've been trying to think of a single quest in NWN that had many different possible solutions (3 or 4), and to the best of my recollection there isn't one.