Ah thanks to Jexmen for that, he found some renderings, a couple of them never seen before.
We know it's foot connected to D2 alone is a significant improvement, I'm just still curious about what it brings to the skyline.
http://www.arcora.com/projets/tour-air2-a-la-defense/
It is something, quite a noticeable addition. Although only an 800 footer at least can now make a real difference for the skyline in there.
Mah, the thing is that district was made to also feature a great skyline after all. It'd be completely wrong to be modest when it ain't supposed to be so. Right?
Of course I'm right.