Not sure if anyone has really posted it recently but yes it still works. What I remember doing was beating Atlas the first time on easy and reloading my save and changing the difficulty to "Hard". I then began fighting Atlas beginning to end in Hard. It was actually easy for some reason. Just make sure you can turn your Vita-Chambers on/off or it won't work for some odd reason.
Note: Does not work with Bioshock 2 or Bioshock Infinite.