Just finished the mansion mission - that was genuinely excellent, I really enjoyed it. Getting there was fun, now that I know not to just steam through groups of enemies, and plotting how to enter the house was cool, if simple. Sniper rifle and invisibility for me, but I haven't yet tried any other characters. I also cleared out a couple of nests and got a high damage pistol that makes fighting a bit easier.
Shame that the thread raging/gloating about the review scores is 60+ pages when the one for actually playing the game hasn't yet made it to 5, but I'm really getting into this now. It's not Dishonored level but it's not bad at all.