If you can't tell the difference between > 60hz and 60hz, you may want to get your vision checked. I'd say once you get to 75-80hz the returns start to diminish

If you can't tell the difference between > 60hz and 60hz, you may want to get your vision checked. I'd say once you get to 75-80hz the returns start to diminish, and by 120 things are hard to notice, but 60hz and 120hz differences are definitely noticeable.