Compared to the NWN1 (Aurora Toolset), ther NWN2 Toolset is much more powerful. (Well, the game developers did use it to create NWN2, didn't they?) However, you would do well to watch out for the following pitfalls.
You may wonder, why would such a "new" game be plagued with problem... Well, for one, NWN2 was developed way before its release date on November 1, 2006; way, way BEFORE Windows Vista came into being. While the game ran okay in Vista Preview (Beta), those who tried running the Toolset in Vista Preview simply ran into the wall! (The Toolset would just crash.)
Even after Vista was released, there are reports of problem between the NWN2 Toolset and the OS, particularly the 32bit Vista. Strangely, feedback from the forum seemed to indicate that 64bit Vista do not have the same problem as the 32bit vista. Most of the time, the problem had to do with the visual theme (Aero) implemented in Vista. So one quick-and-dirty workaround is to turn off the visual theme -- an example being the Terrain Tool workaround listed below.
A. Terrain Tool problem in Window Vista