I'm really hoping that realism will push the limits.
Oh I think its going to do that
Taken from steam forum's
Realism Game Mode
This mode, which Chet says is aimed at extremely hardcore players who find Expert too easy, can be selected on the lobby screen. It is a distinct gameplay mode from Campaign Mode (though it uses the same maps), and can be combined with any difficulty level.
The main difference between Realism Mode and Campaign Mode is that many of the crutches used to make gameplay more streamlined have been removed. For instance, most
haloshave been removed. This makes precise communication much more important, since Survivors can get separated very easily when they can no longer rely on halos to find their comrades. Halos have also been removed from Special Infected when they pounce or drag Survivors.
Halos have also been largely removed from items, making careful exploration more important. The halos only appear when Survivors are within a couple feet of an item.
Damage has also been modified for Realism Mode.
Bullets that hit Infected bodies are much less effective, making headshots a necessity. We don’t know the exact extent of the changes in damage, however. Based on gameplay, Survival mode may also cause Witches to kill Survivors instantly (instead of incapacitating them on easier difficulties), but otherwise, Realism Mode doesn’t appear to alter the health mechanics of each difficulty level.