There are absolutely no where near 6 hours of game play in this game. Maybe if you spend literally the whole game not working on the story. I didn't rush it, I spent time running around looking for things, I didn't just speed run it. This DLC is way too short.
I missed one audio diary, so I'd say I didn't look enough.
I will say I think I lost an hour or even two because the game had a major bug... I reported it and a developer should have relayed my save files to the devs. Basically, Elizabeth disappeared and as such cutscenes with her nullified.
Still, I took a while just listening to things, looking around, dying from lack of resources... Etc...
