Monitor close to head = hard to see everything so it's easier to play on 4:3.
But you can set 16:9(10) and disable scaling in gpu card, then your screen is smaller and you can see good like on 4:3 ratio.
Up to ones own preference.
Having a screen stretched wide, makes aiming easier horizontally.
While having it more squeezed, makes it easier to aim vertically.
I played 4:3 stretched, so I had an easier time flick hitting sideway shots.