While in the Palo Alto store yesterday, I went to try the retina mini to see if I should get one in addition to my iPad Air. Since I use it for reading, I opened an iBooks page and found a gray overcast in the background. In addition, I found jagged edges in the fonts. Thinking that it might be my eyes, I asked a young sales rep to compare the retina screens on the mini and on the Air, using identical pages. Sure 'nuff: No gray overcast or jagged font edges on the Air, but definitely on the mini!