I had an ingenious idea to solve the vita-chamber issue. because I'm brilliant.
Okay, I'm doing my second playthrough on Hard. And it feels exactly the same as playing on Normal. Perhaps because I'm better at it now, but mainly because the vita chambers makes difficulty totally meaningless.
The man in the interview says it is all about providing choice to the player, so now I start thinking about a way to provide choice to the player regarding the vita-chambers. toggling them in a menu is lame, frankly, but what if (in a sequel, obviously) there was an optional quest of some kind where you can choose to strip components from the chambers, giving you some kind of unique benefit but destroying the chamber in the process.
SO here's my scenario: your path is blocked by a biological barrier (plants, a gross wet thing, etc) a character contacts you and wants you to take a component from a VC to them. When you do, they get you to use it to create a "power bomb" kind of thing which damages all creatures in a single room other than the bearer (an "ultimate nulifier") - then after the initial quest bit is done you now know how to strip future vita-chambers for this component and make more ultimate nulifiers at u-invent machines.
Thus giving the player choice for a one-off benefit in exhange for choosing a higher difficulty, all handled in-game. I want to see more of that, Halo has the in-game y-axis selector, how can we get more game options to be created through gameplay? difficulty selection through play choice is very very cool I think.