I just finished Dishonored + DLC, the base game 2 times on hard, one on no-kill, no-alerts, no skills and the second one was a bloodbath. The DLC was only one on hard and no kills and no alerts. Was 29 hrs(some idle time) and 46/80 on achivement (57%).
It was a rewarding and fun game, much better in the ¨without deaths¨ runs. Is not really hard to achieve because the power of wink is way too powerful, the kill everything run was fun but it was just overpowered and lose essence of the game. The story was okay, nothing great but fulfilled with twists in the story(predictible but still), give a reason for revenge and a goal. But what I really liked was the world in general, a world who suffer the plague, a sick and degenerate oligarchic class, the great atmosphere, and character design.
I'm not a person who would attract a lot for the DLC, unlike always end up playing more by duty than by choice, because I feel is just soulless content, these are good, follow the same path but with a different atmosphere extending this world.
I know this more than a current recommendation is a LTTP, but still buy it and/or play it.