I enjoyed the Explorer Pass for the Big Bus Hop On and Hop Off, and the boat trip. It was not so good for the Willis Tower. There was a wait to get on short elevator ride to security, then long line there, then you had to see a movie, then a wait for elevator to go to top floor. The pass did not help at all for the long waits.
A lot of value for the money paid.. totally recommend
I think the Explorer Pass works when you have several days to use it...it was not my case, since I only used it one day. I enjoyed the Field Museum, to me, the best attraction in Chicago together with the Architectural Boat Tour. However, I did not like the fact that if I wanted to see several of the collections displayed in the Field Museum like China or Vikings, I had to pay separately an extra 18. I think I should have been told about that in advance. THank you.