I'm going to be looking for a new graphics card soon if my GTX 980 4GB doesn't work after baking it (you can read about that here).

I'm currently looking at getting the GTX 1060 6GB, but not really sure why I should pay the extra 100 for a 6GB card. (the 3GB being priced at 200 and the 6GB at 300). What are the differences I'm going to see by having 6GB DDR5 Vram rather than 3? Is it just for extra displays to run at better FPS? Will I see the same amount of FPS on both cards, regardless of the VRAM?

I need help here.