Originally Posted by J_M_Tungsten
Actually, the trade centers were 208' wide, Aon is 194'. I doubt the trade centers had 14' of floor space from the cores.
Well just using your numbers and doing simple math, you have a floor area of 3.123M SF for Aon Center and 4.759M SF for the WTC (not rentable area, which is closer to 2.3 or 2.6 million SF for Aon Center and less than 4 million SF for WTC). Also, I can't find a source for the width of Aon Center, but I found an offhand source for the dimensions of the WTC cores: 87 x 133 ft wide. That is a massive core, but efficiently small for a building the size of WTC. I think the WTC mastered the art of sky lobbies, thus reducing the need for a massive core with rows of elevator bays, so it would typically be a lot larger than it was. Aon was in the Twin Towers, too, during 9-11.
Either way, excusing my exaggeration and as beautiful as Aon Center is, it is a dwarf next to the Twin Towers, which each gave the "Willis" Tower a run for its money in terms of sheer size.
I was only responding to comments above comparing it to the WTC, wasn't trying to make a big competition.