The expansion is well worth the cash, even though it's a tad short, I think it's a solid and more polished product then the original game. Bradons Camera Hack, made it even more enjoyable.
I went through once as a Ranger/Rogue/Shadowdancer. I'm playing through a second time now as a Sorcerer. I'm finding several things I missed the first time around and have solved a couple side quests in completely different (but still logical) ways.
I like it a lot...better than the original campaign, certainly.