Theres no "significant" difference if your GPU is good. If you have a high speed camera and test it for yourself the total input lag of the system barely changes. Anything you perceive is placebo. Or maybe the fact that the screen has detail makes it "feel" smoother? Either way theres no competitive advantage to it. Pros didn't always have 1080Tis, as recently as 2 years ago they didn't, and back then it did actually make a small difference.
Also if you're GPU is at 70% then thats pretty high, so there might be a slight difference. Its not the same for pros who have much better GPUs.