But thats with extreme value changing. Having to eat, sleep and drink per day, Stimpacks healing over a few seconds and ammo weight didnt make Fallout 3 any harder, I dont see why it will in FNV either.
It does make it harder in that it drains your resources like crazy at the start. The problem with F3 was that your character quickly became this god-like being. With the eating/drinking/sleeping, especially when your attrition values were turned way up, early on it forced you to spend money on food, water and shelter. Ammo, guns, and armor, you bought with whatever was left over.
It also requires a little bit of role-playing, as even with those handicaps, yeah you could still raid a harder area of supplies, just save before hand and keep reloading till you get it right, then be set for some-time until you level up a bunch. But if that's the way you play, you can't blame the game for not being hard enough. It's you fault for abusing the load/save system.
Regardless, high attrition rates, higher damage, more expensive supplies, ammo weight svcking up your carrying capacity (limits your profit), fewer supplies around the world, paying *huge* prices for fixing crippled limbs, Marts Mutant Mod with increased spawns, and (maybe the most essential) greatly lowering XP gain. Made the game quite a bit harder.
Maybe you played the Wanderer's edition, but it requires a lot of tweaking to really make the game hard. I wonder if you bothered with any of that.