Reviewing the Ray-Fan plots and spot diagrams in "Telescopes, Eyepieces Astrographs - Design, Analysis and Performance of Modern Astronomical Optics" I think the argument may not be so much about aperture as scope design. Fast refractors inherently have relatively lower resolution compared to slower, large aperture catadioptric systems (e.g R-C, corrected Dall-Kirkham, corrected Newtonian).
Tiny pixels only produce better resolution if the optics support it and even the amazing FSQ-106ED won't benefit from tiny pixels. Take a look at these spot diagrams which use a 100 micron scale:
http://www.takahashi-europe.com/en/F...tics.spots.htm Measuring generously, at the centre of field you're looking at 10 micron spot size. And that's a high-end refractor/astrograph...
Cheers,
Rick.