I'm a Rogue (10) / Champion of Torm (2), a good 10 000 XP short of my next level (don't know the count offhand). I'll be kind but firm with Linu, and then go sewer-diving '>
Luskan is my favourite part of the OC. I've never noticed the experience for each kill, but always gain a level for finishing the town (making sure I take out both captains), and another level for the tower (making sure I take out all levels).
From memory, xp's from kills are less important than completing quests.