> Most test and site you play seems to show our maximum response rate to click at somewhere between 200ms to 300ms, with most scoring 250ms+ range. And yet we can still feel the difference.

I think when you interact with a UI (or a physical object, for that matter), you're projecting an expectation into the future relative to your sense perception of the action. So the ~250ms delay applies to both the action and reaction, thereby effectively canceling out.