Do you think there is a noticeable difference after post processing -between] a D610 and a D800/810 landscape or portrait photo. The 810 may have more pixels but how many is enough for its size sensor? I'm quite happy with my 610... Granted the crop factor is greater but what else??? I know about the more focusing points but will it matter in the end??
All other things being equal, I wouldn't be able to tell you which camera (D800/810 vs. D600/D610) took a particular shot. I think we hit a Point of Diminishing Returns some time ago in the ever ongoing mega-pixel race, but that's just me...What you can't deny is the pixel density of the D800 series is 50% greater so the difference IS there but too many people confuse resolution with sharpness and that's a shame. Much like a great wine, just because
your palate may not be able to discern the difference between a wine costing $20 bottle and a wine costing $200 bottle doesn't mean there is no difference to be discerned.
I'm not sure what you're referring to when you say "the crop factor is greater..." but it's early here and I'm semi-sleep deprived.