Quote Originally Posted by arthurking83 View Post
in many cases this may be 'correct' but from what I've noticed, diffraction is more about lens design(design brief??) and less about the size of the sensor.
Partially. Go back and look at the technical link you posted.

Where diffraction is occurring if the film plane is closer to the aperture plane you'll end up with less noticeable diffraction (but it's still there). If you move the film plane further away from the aperture, the light spreads more and thus you get more diffraction effect.