Just wondering, can my companions die permanently.
I currently have ED-E as a partner and it seems he only gets unconscious when his health reaches zero, are all companions this way, or only ED-E because he's a robot?

They only die in hardcoe mode, otherwise they are essential NPCs and onyl get knocked unconscious.

Aye, they can be killed permanently in hardcoe mode, I've had this happed to Ed-e myself.

In hardcoe mode, I find myself using VATS way more often than I otherwise would just to make sure ED-E doesn't die.

Wow, I actually really like that, in fallout 3 I was always turning around to check to see if my companions were ok, and now I'll have the challenge of keeping them alive when i play hardcoe mode.

I agree it's important the companion be vulnerable to death. In regular mode, they go unconscious, which is nice, but also will try hardcoe mode 2nd time around.