It was a beautiful evening/night and pretty clear. Shooting from one of the top seven tallest buildings in north america (JOhn Hancock building) with three of the top seven in north american in view was very enjoyable.
Used a little Gorilla Tripod on the short ledge in front of the window. It look an hour to get to the elevator, which was much longer than I was told it would take earlier in the day. Should have arrived earlier or bought an express pass. I would advise arriving at least 1 hour before the time you want to start, and I would suggest the best light is 30 minutes before until 45 minutes after sunset.