As a person who loves Fallout: New Vegas, and loves challenge in games, the Very Hard difficulty in F:NV has always been as disappoint to me. Difficulty essentially being damage ratios can be a passable concept, but the original Very Hard difficulty simply made you deal half damage to all opponents while they did double to you. It didn't make the game feel particularly more punishing as much as it made a need to be over-leveled and have excess amounts of ammo.
This mod, simply, changes those modifiers so you take three times the normal amount of damage, but deal twice as much. This is meant to take difficulty in a different direction, and making encounters more fast paced with higher stakes. Taking down an opponent itself is easier than before, but a more risky endeavor. 

Warnings:
This mod, by nature, has some unintended balance changes. Melee characters and monsters are now a lot less of a threat, which does include Deathclaws. In the past I tried tweaking values in the game to balance this out, but in the end it was a mess and overall not worth it unless I was willing and qualified to essentially overhaul damage / DT values in the whole game. Instead, I just toned down the damage modifiers a bit to compensate, but don't expect to be running around with a lead pipe and not get your head blown off.

Conflicts:
In it's current state, this mod is literally too simple to cause conflicts. As such, it should work with any other difficulty/gameplay altering mod. At worst, if another mod also changes the same values, the mod first in load order will take priority.