I think I see where you're getting. but confused by your analogy's.
This was also interesting.. diffraction. Wouldn't saturation cause the PSF maximum to be larger than the airy disk over x time due to the diffraction. got me glued to the screen now.
I don't know how this incorporates into your Hubble comparisons though..
http://www.willbell.com/aip/haip2_chap_1.pdf
Pg 29 - Section 1.5.4