AMD's smoothness factor put to the test by AMD & HardOCP...

[Final8ty]

All I can say is - if there is any kind of difference it should be measurable - be it through fps graphs or some app that simulates the mouse movement and then measures the lag from the input to the frame being drawn..

The problem, is to too often enthusiasts only think of FPS when there are many other things that lesson the experience.

Tearing
Slight pauses due to textures loading, trigger points, streamed environments ect... and very little to do with raw FPS.
Some systems handle them better than others.