Has anyone done this and is it worth doing?

I'm not sure, IIRC when I didn't level up right away the amount of XP went down anyway.

If I understand you correctly, it's like in BG, where you have mountains of xp, but are still lvl 1? If that is so, no, it won't work in NWNs.

Well, I've been doing it and it seems to work. I'm running a Cleric at lvl 5 who could go up 2 lvls at least now; havn't checked for a while. I did lvl her and found I got less exp when I did, so I'm leaving her at lvl 5 for a while.

One thing to note is that the XP given to you from slaying creatures isn't based on your level, but the amount of XP you have. The amount of XP rewarded to you is lowered once you pass a certain threshold of XP that would gain you a level. So by not clicking the "level up" button and continuing with your questing, you are gaining nothing, and shooting yourself in the foot by losing power [img]smile.gif[/img] .

Well, I'm at lvl 5 and if I lvl up I get less exp than if I don't. How can that be? I tried it both ways.

Sometimes, the way the Challenge rating is figured, you may progress a few lvls with the creatures spawning at a set lvl. I've gotten more xp for spawns after a lvl up than before as well. I think that part of the problem is say that the CR changes at lvl 6 for one group of monsters to the next. If you come in at lvl 4, and then get the xp for lvl 5, you would get less xp that way.