If you’re thinking about it, just buy it!
We thoroughly enjoyed our CityPASS and were able to make it to five of the different Chicago locations. We reserved spots at some of them ahead of time through the app and were admitted to each with ease upon arrival. We also were able to easily select the add ons when we arrived (ex the 4D movie at Shedd Aquarium). We would not hesitate to purchase these passes again when we’re back in the area!