Thank you all for your responses to my posting!!! Your wide-ranging comments and illustrations provided the kind of information and guidance which I had been looking for.
Re. "perceived sharpness", I'm thinking of the (instantaneous) appearance and impact of how sharp the images appear to be.
I don’t recall reading forum discussions about the differences in perceived sharpness between full frame cameras having pixel-count between 20 and about 24 MP and those with pixel-count above 40 MP. I’m specifically interested in learning from the users of the high pixel-count cameras how much of an improvement in the perceived sharpness you may have noted in your cameras’ images compared to the lower pixel-count versions. I’m thinking about the non-processed, SOOC perceived image sharpness comparisons. Thank you, and Happy Holidays!