The iPad Air 2 features an improved display, which includes a new bonded construction that eliminates the air gap between the display and the cover glass. It also comes with a new antireflective coating to reduce glare in situations when there is high ambient light.
A major innovation for the iPad Air 2 (that is not fully appreciated) is an anti-reflection coating on the cover glass that reduces ambient light reflections by about 3:1 over most other Tablets and Smartphones (including the previous iPads), and about 2:1 over all of the very best competing Tablets and Smartphones (including the new iPhone 6). [...]
Overall, however, they arent all that impressed:
However, other than the new anti-reflection coating and bonded cover glass, the display on the iPad Air 2 is essentially unchanged and identical in performance to the iPad 4 introduced in 2012, and is actually slightly lower in performance than the original iPad Air (for example 8% lower Brightness and 16% lower display Power Efficiency) most likely the result of an obsession with producing a thinner Tablet forcing compromises in the LCD backlight.
DisplayMate is even less impressed with the display found on the iPad mini 3, which matches the one found on the iPad mini 2.
In 2013 the mini was given a Retina display, but remained with a reduced 62 percent Color Gamut the only current iPad or iPhone without a full Color Gamut. Now, in 2014 the new iPad mini 3 still only has a 62 percent Color Gamut, plus it was denied the new enhanced anti-reflection coating and bonded cover glass of the iPad Air 2.
They conclude that the iPad mini 3 is embarrassingly mediocre and way overpriced. No surprise there.