Yes you should get the game. Welcome to the Forum.
New Things:
hardcoe Mode that adds, dehydration and the need to sleep. Crippled limbs can't be fixed by sleeping or stimpaks
Damage Threshold so Power Armour is once again Power Armour and not a joke.
Reputation System so the people in the game world for good or ill will know of your actions.
Multiple endings based on your actions. Four main endings.
The ability to join or help almost every faction in the game.
Little to no level scalling so there are enemies greater then your ability to kill.
The game is more advlt then Fallout 3.
More Quests and more unmarked Quests. Companion Quests.
Traits
Ability to make chemicals and cook food.
Ability to make ammo and recharge power cells.