The complainers are right, in my view. Not only does my own iPad Air suffer both the uneven lighting/coloration, but there is also the book spine effect. In addition, some variation of these two flaws is visible on almost every iPad Air I have seen in stores. In some case the book spine effect was so pronounced it was hard for me to believe it was being used as a demo.
Here we go again. I had a similar problem with the first generation of Retina displays in the iPAd 3. I ended up going through several exchanges before getting a unit that was least bothersome.
Granted, this is the kind of screen anomaly that is noticed by and then bothers a certain type of user. Some of us are more sensitive to detecting subtle color shifts, and then there is a subset of those people who are bothered to distraction by it.
I am one of them, and I wish to hell I were not. Once you notice the unevenness in the display it is all you see about the screen. Some people call this obsessiveness, and it surely may seem that way to the many who will look at these screens and deem them perfect. But the problem seems quite obvious to a number of people in the forums -- many of whom, like me, see this problem on most of the demos they check. And these are people who clearly are predisposed to liking Apple products. They are the ones who bought the Air on day one and are on their second or third generation of iPad.
It is not as if Apple is being held to a higher standard. My Google Nexus 7 display is superior to the Air in its whiteness and evenness.
My question regarding the issue to Apple's press reps has gone unanswered. The issue du jour for Apple is the revelation that the iPad Mini with Retina display does not have the same strong color gamut as its larger iPad cousin. Anandtech measured this issue, and so it is getting widespread pickup by other press. The yellow tint problem I am seeing on the iPad Air is a more subjective call, of course. But a lot of us are making the call and wondering about Apple's quality control.
The screen is, after all, the iPad's lead feature -- although the new thinness of the Air is sublime. One has to wonder if the smaller number of LED sidelights used on the IGZO display for the Airs helped create these uneven lighting problems. It is hard to believe that the same mavens who tout the micron-precise manufacturing process for their work-of-art devices somehow missed that a lot of their LCDs look murky and yellow.