... Even my wife thinks the resolution looks more crisp on the Pro over the Air 2 even though they are the same.
I get the same impression. I wonder if maybe the display on the Pro has more contrast or more brightness than the Air. I don't know the terminology for displays, but even with the same pixel density, brightness could be different. Also, though the pixels mper inch is the same, any given picture has more total pixels. Put it this way: If you took a high-resolution picture of a foot ruler and then displayed it on an iPad Air and on an iPad Pro so that the ruler took up the full screen width on each, the larger size would mean that the Air has more pixels for each inch along the ruler in the picture. That would (?) make the picture look sharper.
Whatever the reason, maybe it's that, maybe it's a brighter screen, or maybe it's just an illusion or a trick of the brain, the Pro really does look sharper to me.
OTOH, board games and card games feel nicer on the iPad Air. Those don't need the large size and feel more natural on the smaller screen. I play chess on the Shredder Chess app (5-star app, BTW) and it's easier to get the feel of the board on the smaller screen of the Air, which in turn is better than the slightly-too-small iPad Mini.
On another note, this morning it looked as though there were a lot of irregularities, sort of waves, in the screen when I held it up at an angle to the light in a dark room. So I washed the screen, and those disappeared. I've been smudging it with my fingers. Note to self to keep the screen clean. Is there a "best" way to wash the screen?