What is the benefit of using V.A.T.S.?

The V.A.T.S. system is a throwback to the old turn-based system of Fallout 1 and 2. It caters to the wishes of the players who preferred turn-based and/or are bad at FPS style fighting.

Personally, I would hate having to fight FPS style all the time, as I get motion sickness easily when I have to constantly turn around to keep the cross-hairs on the raiders circling me. Normally I play stealth and pick off my targets one by one, but when the brown stuff hits the fan, V.A.T.S. allows me to pause, re-orient myself, and get off a few close range shots that actually hit the target.

Vault-Tec Assisted Targeting System (VATS) allows you to slow down time and target specific parts of an enemy, target specific parts of a group of enemies, and trigger critical hits. Since the game is an RPG-FPS, this caters for the fact that many players may not necessarily be FPS fans and acts as a throw back to the turn based combat of the original Fallout games.

While there is nothing stopping you from shooting the legs off a synth without VATS, VATS allows anybody to shoot the legs off a synth.

V.A.T.S slows down time and allows you to select parts of the enemy to attack. If you aren't the best shot, or you are versing a fast moving enemy then it uses what is basically "turn based strategy" attacks which have a certain chance to hit (depending on the weapon you are using, the distance of the enemy etc.). It also tells you how much damage you attack is going to do to an enemy. V.A.T.S also allows you to perform special moves on enemies when using unarmed or melee weapons. It also allows you to clear a room like a badass xD

While I would agree Fallout 4 has enough FPS elements to render VATS unnecessary, I still find that it provides many benefits to the user.

For one thing, I can't tell you how often I saw someone lunging at me, stopped time, aimed for their head, and killed them in midair. While this is really cool, it's also very useful.

In most FPS games, the first thing you do when you get jumped is try and aim for the assailant, and with little time to react you'll probably have to go for the chest. With VATS, all you need to do is push a single button, and in close-quarters situations you suddenly have a 95% chance of pulling off a no-scope headshot. This is similar to the optimal strategy in most game shows, which is to push the button before you have the answer, since you'll get a few seconds to think of it with absolutely no threat of someone else answering first.

I might also point out the added benefit to console gamers, who don't have as much accuracy or turning speed as someone aiming with a mouse.

Without V.A.T.S. I would never be able to shoot anything flying (like blood bugs), so it's easier to auto-target them. I'm also a sucker for flashy animations so naturally I love ending the fight with a critical head shot (and yelling some swear words).

It's not for everyone, but it's a fun element to the game. Like other people have said, it's also nice to look for enemies and locate land mines before you step on them :).

VATS is a handicap and punishes those who want to play full fps. Thats all. I played all the orignals, and for their format of course it was (turn based) absolutely necessary. Not so much in first person. Its a stupid feature. < Personal opinion.