I've grown to despise the term "immersive". Different meaning for every person, thrown around all over the place in thousands of ways, and mostly (in my experience) used by people as a club to wield against anything they don't happen to like ("_______ ruined mah immershuns!" )
Me, I just play games and enjoy them. As far as I can remember, I've never suffered from this "immersion" malady in the 35 years I've played games. Which, based on how much it seems to cause games to be ruined for people, sounds like a good thing.
edit: and, given all the things I've read on the Beth forums the past 5 years about "immersion", I'm not sure how FO:NV's hardcoe mode could have provided it. Minor differences in inventory management doesn't particularly seem "more immersive" - it's still moving lines of text around in an on-screen menu. And the "Eat Now! Sleep Now!" meters certainly can't be more immersive, since they're more UI... and having UI on the screen is an intrusion that "ruins immersion". As well as the game telling you do to things reminds you that you're playing a game/exposes game mechanics. Which is also, apparently, an immersion-ruining thing. Eh, whatever.