I received the Lords of Waterdeep: Scoundrels of Skullport expansion for Christmas. I played it today, and lost, but I think it was close enough not to be a stomp.
One thing that bugs me about Lords of Waterdeep is that virtually EVERY game, I end up realizing when the next player is taking their turn that "Oh, I didn't get a cube / 2 VP / whatever" that I was supposed to because I didn't check every single plot quest in front of me every turn. There gets to be a lot to remember sometimes, at least if you're dumb like me.
Finish quest type A? 2 VP. Quest type B? 2 VP. Play any intrigue card or move on any square that gives orange cube(s)? Extra orange cube. Get any money from doing that instead? Extra black cube.
I also finished a powerful quest that would have given me three agents back...only to realize instantly that I only had one agent placed. Whenever this happens, or the thing above happens, I feel like I'm cheating if I try to take anything back or fix the missing stuff, so I just leave it and feel bad.
We only played with the Undermountain module (not the Skullport module which is in the same expansion). Undermountain has some VERY powerful quest rewards -- most normal quests give maybe 5-10 points of reward more than is invested. My girlfriend finished a quest that took 10 cubes and gave 40 VP -- bam, 30 point profit. It took something like 5 white cubes that are hard to get, though.