If there is any difference between output of graphics hardware, this must result from bugs. One or other card must not be displaying what the software is telling it to. (Assuming they support the same DirectX/other API version.) The right way to present the results would be a bug list, not graphs of "quality".
When "quality" includes something like "HD noise reduction" and "skin tone correction" you know you are being scammed. (These have a valid function in editing, not playback.) The main current problem with quality of playback is lack of color management. Again, this is not a hardware/driver issue but needs to be fixed by improving software and graphics APIs. Same goes for frame rate interactions. (Upscaling is unproblematic.)