In NWN I added CEP and several other hak files to my module. It took a long time to work on integrating all the additional content so that it all looked like it was there from the beginning, not just "added in indiscriminately" after the fact.
The bad side of making my module more "complete" and immersing, was that the number of potential players who were willing to download the extra content (probably took at most 10 minutes on a decent connection if you already had the CEP), was obviously smaller. Also, nobody could see the server in GameSpy and login out of whim and be hooked by my 1337 DM kung fu....

Now NWN2 is different. Everyone has no choice but to subject themselves to a lengthy download if they want to play MP (outside of the OCs of course). In addition, the average PWC file is probably equivalent in size to a hak file. So, MP interested people already know the price of admission, regardless of whether or not the movie is bad (if you get my meaning...).
In light of this shift from "nice to have" to essential, are people adding custom content to their games and, if so, are they finding any negative impacts on the size of the player base willing to try out their games?