I guess I'm comfortable with BG1's "short term C&C" -- so long as something really changes based upon my choices, I guess I don't need the whole game world to shift around. If a choice in BG1 opens up one new option related to a quest I'll get in an hour, and another choice means I keep or lose a companion, well, to me, those small things are enough. Those small things are greater than my experience with NWN 2, for example. When I replay BG1, I can have a different experience each time. With NWN 2, I will follow the exact same path, do the exact same quests in the same order, and with the exact same companions.
For example, from Wikipedia, about my previously mentioned Monty C&C:
At one point in the game members of the Zhentarim will attack you unless Xzar and Montaron are in your party. A Zhentarim agent will also appear and offer the party some advice on defeating Sarevok if Monty and Xzar accompany the party during the game's final chapter.
There are lots of little things like that, and they change the experience enough to make replays not only tolerable, but enjoyable. Also, since so many areas are optional, you can work out various paths and have new activities for a number of playthroughs.
The only part that grates on me is "running the gauntlet" of 6 or 7 required areas leading up to the city. I didn't mind them the first two times, but having to fight all those spiders for the 7th time got a little lame. Still, even in that, there are choices. For example, I've skipped Coran to avoid his wyvern caverns, making those required areas a bit faster to complete.