Rich, I thought the same thing, but surprisingly enough it's pretty steady throughout. The only real difference is down below the plexiglas at the very bottom. We checked. Also, that plexiglas shelf is actually not all the way from front to back, there is actually a 2" gap front and back, so it circulates really well.
I did the Accurite mod from here, and so far the temps inside and outside of the egg box stay within .5 degrees of each other, and the humidity in the box just says HI.
Gale