the sky's a little too saturated for my taste. and the burj's color is off since it's not that blue. it looks more of a grayish-darkblue.
I definitely think Greendland Plaza, Guangzhou IFC, Trump, Jin Mao, and 2IFC should be included. But seeing as the "Freedorm Tower" is included in there, the Al Hamra (which is already topped out and has a fantastic diagram) and the Kingkey Plaza (again, there's a good diagram) should be in there as well. i wouldn't mind paying more money for all the buildings.
The only 400m building not included would be the Makkah Clock Tower. The most recent one doesn't have enough quality and the other ones are old designs. But I think it'd look awesome if we did have a drawing of just the main tower. It would also even out the height difference between the Burj and the rest of the buildings. The only reason why I wouldn't place it on there would be the emotions of people building the poster. I'm perfectly fine with it, but I wonder if having the WTC and the Makkah Tower on the same poster would offend some people (there really isn't anything offensive but... you know people!).
As for the diagrams chosen, I think it's great that it has drawings from various illustrators, but we should focus more on quality (the only ones I have a problem with are the Burj, HK Commerce Center and the Shanghai WFC).
just my 2 cents