Ya know... it's a bit sad how most games just have regenerating health these days. I do think it streamlines the gameplay, but at the cost of removing a lot of the difficulty.
I think they just really went too far. Cause the original Doom model... just picking up healthkits and using them as you walk over em, is outdated. It doesn't work well enough for today's games. Good players end up not using up health kits because they're already at full health, and then later might require a healthkit but can't get any because the level designer decided not to put any down at that location.
Mulling it over, I think the healthkit-in-inventory system is still probably the best. Like in Jedi Knight, Max Payne, or Deus Ex. You pick up healthkits, store em in your inventory, and use em when you need to. I really liked Max Payne's... he just carried around some painkiller pills. Far Cry 2's was a pretty good implementation too. You get these syringes to inject yourself with, but first you'd have to pry the bullet out and cauterize the wound to stop yourself from bleeding out.