First, I'm perfectly aware you're not debating which is better, simply which is more realistic. That said:
Soviet Heavy said:
So called "realistic" games have done away with the health bar in favor of the get shot, regenerate form of gameplay.
To call this realistic is moronic. I'm not saying that the mechanics of a health bar are any better, but the concept is much closer to realism.
For example, a Health bar can represent how much a soldier knows they've been hit. Looking at it from an in-universe example, the soldier knows they've been hit, and should move with more caution until they can find a way to patch themselves up.
I wasn't aware soldiers had a graphical or numerical representation of the objective relative damage they've taken. I, for one, have suffer my fair share of injuries and damages and have never noticed a graphical or numerical representation of how much damage I've just received. Maybe it's different when you get shot. Generally when you're hurt all you get is pain... You can try to estimate how badly you're wounded from our much it hurts, how badly it affects you, and how it looks (providing you can see it)... But that's it... Mhh, wonder what system does that whole "No objective numbers, you gotta try to estimate how badly you're wounded by how it affects your performance or the visual cues" thing.
Speaking of which, did you get get shot or had a serious injury, such as the kind one finds in most videogames? I never got shot, but I've had my fair share of serious injuries, as I mentioned before. As such, I have to ask, can you PLEASE tell me where you can find those magical health kits that instantly makes everything better? Usually I take some painkillers, get surgery if needed, maybe take some antibiotics depending on how bad it is, and wait for my body to heal... Wonder what system does that again...
Soviet Heavy said:
With the regeneration, it doesn't matter how badly you're hit, all you need to do is duck into cover until you grow your limbs back. You don't need to know how bad it was, you don't need to think over how to change your survival strategy, you just get back up and do it again until they die.
As opposed to simply walking over/using a magical pill/medkit that makes everything better in a few seconds?
Soviet Heavy said:
The health pack pickup method of healing is about as close an approximation of real world first aid this side of S.T.A.L.K.E.R. It forces you to take time out of combat to find a way to heal yourself, just like medical aid in the real world.
There are several regeneration systems that do that as well... Namely ones that only start healing once you haven't received damage in x amount of time.
Also STALKER's system is a mix of both. You take something to trigger a process of regeneration, which honestly is the most "realistic" system.
The MOST realistic I've seen is also an hybrid: America's Army 3. Again, slow and limited regeneration. If you're incapacitated you need medkit and assistance from a fellow team mate, and you can only heal a small portion of your life back, depending on your injuries. Some injuries are fatal, and therefore you can't be helped at all.
Either ways, games are about fun, not realism. That's what simulations are for. Both systems can work, it depends on how they're applied (see TF2 Vs. Monday Night Combat). Personally I prefer regeneration, but health bars can work too.