Heres the issue i have with the game's "difficulty". At normal level and even easy, it takes multiple shots to the head to kill someone. That is fantastically idiotic, and I hated this in Fallout 3 as well but forgot all about it until I started playing NV and I had a wave of despair hit me that i had to engage in this god awful combat system again.
Difficulty should not rise or fall with the sacrifice of realism as all it does is take you out of the game. If it were another type of game and not an RPG or realism based FPS, then I'd have no issue with having to shoot someone multiple times in the head to down them, but all FO3 and NV is doing to increase difficulty is taking the lazy way out and making you shoot things more times. That is pure baloney.
The difficulty increase that comes with hardcoe mode isn't really difficult at all more so as it is just something else to keep track of in the game. it doesn't make anything harder or easier in any way unless a few extra button clicks truly makes life difficult for you.
What a good difficulty increase would be is a true AI intelligence scaling. hardcoe mode and harder difficulties should give extra armor to the NPC villains, make them hit harder in melee, equip them with better weapons, and improve their accuracy. Not just have the game make you plug more bullets into something and call it "LOL HARDER DIFFICULTY!"
I just have this feeling that some things were just tossed in the game as an afetrthought with the devs knowing the community would mod it to something "better" anyways.