Thanks, I really like the first. By the way, us Chicagoans will probably never stop calling it Sears Tower, no matter who owns it. Lord knows I spent enough time in traffic jams around it when it was being built!
As someone who only visited Chicago once many years ago, I also remember it as the Sears Tower. The first image is very nice. For the second, I'd be tempted to increase contrast a bit and straighten the verticals.