I'm not sure how much of it is psychological, but it feels like 10mm, maybe less even, of bar height up/down, or fore/aft, makes the difference between a bike feeling "ehhh" and "extension of my body".
When I get the height and length perfect, I'm a different rider.
On demo bikes or if I try a friends bike it seems I'm expect it to feel odd and I'm not so picky, but on my own bike, it's like princess and the pea. That last 10mm.
Am I nuts?