Well Gsync is for people that play at a variable frame-rate, in meaning the GPU is always 99% with the frame-rate going up and down from say 90-144 (still very smooth) due to graphics demand.
You will see tearing if you don't use some kind of frame syncing. Going 144fps for gaming pretty much requires Gsync if you hate tearing in games thou it is frickin expensive and i would know as i have a Dell TN 1440p one but 1080p is just as expensive.
There is nothing wrong with just getting a bob standard high quality 1080p 60HZ monitor, i lock some of my games down to 60fps (bethesda games) as they don't run optimally with variable 144hz.
If your just a casual gamer that plays the odd RPG or multiplayer game a few times a week such as...