Yeah. I spent almost endless hours just using Kamiryns' CBC to make every character concept I could imagine, and then testing them out in a custom battle arena mod I created. I've never seen a game with more replayability.
Imho the NWN series set the bar for modability. Simple mods can be made by anyone.. and there are very little limitations for the advanced mod makers. I own all the games in the series and nwn is my preferred modding platform (nwn2 is prettier so i use that when possible although some already built in functions make nwn easier/faster to mod with in certain situations)
The fact that the script language is pretty much modified(and simplified) version of C with a built in compiler made it seem like learning the language was far easier than say.. python. (I tried to learn python I really did.. but that language is horribly more complex imho)
Speaking of nwn2 modding **wanders back to nwn2 to keep working on his empire ruler mod**