Must be most of the way through this now, on the Flooded District mission. I haven't killed anyone yet (except one guy who I meant to choke out but accidentally put a knife in the throat and had to reload), and I don't intend to unless I play it through again. I still think I'd try and keep the stealthy aspect going, but it'd be fucking satisfying to shoot someone in the face when I got in a tough situation instead of having to improvise an escape plan on the fly, or just get killed.
Despite the non-lethal playthrough attempt, I'm surprised at how the usual good/bad morality system doesn't really apply here. A few of the options I've taken with main targets almost seem worse than slitting their throats before they know I'm there.
I don't know how anyone could rely on the autosave for this game, I'd have thrown a pad through the window. Hell, it tells you to 'save often' on the loading screen for a reason. I really enjoy the level of freedom you have in this game. Out of curiosity, I watched a walkthrough of a part I'd already done on youtube, and it was almost like a different mission set in the same level.