I tried 4 ipad 4's in a row before giving up. A couple had black stains that could be rubbed off. All had defects out of the box.
#1 - scratch on the back (didn't examine display)
#2 - dented on edge (didn't examine display)
#3 - dust under glass, uniformly pink tinted screen, scrolling not as smooth as others
#4 - no cosmetic blemishes, but has back light bleed on left and bottom right corner, greenish to pinkish color gradient (left to right), and blue tint on edges of screen.
I tried 5 ipod touch 5th generations in row before giving up. All had a hairline scratch on the apple logo. Most had black stains that could be rubbed off. All had defects out of the box.
#1 - nick where glass and chassis met, blue/yellow screen edges, screen started clicking after 1 month of use
#2 - nick where glass and chassis met (didn't examine display)
#3 - nick where glass and chassis met (didn't examine display), rounding on chassis edges uneven
#4 - nick where glass and chassis met (didn't examine display)
#5 - scratch near headphone jack (didn't examine display), uneven gap around the lightning connector.
Apple QC is a joke.