We went on the Mercury Skyline Cruiseline "Urban Adventure Cruise" which does a short bit in the river and then a swing past the skyline in the lake. If I do this again, we'll opt for a river-only cruise. We thought the views of the buildings and architecture from the river was super intersting, and were less impressed with the time on the lake. In addition, getting to the lake, and then back from the lake to the river, is a boring 15-20 minutes each way waiting for the lock to cycle to the direction your boat needs; a big part of the 90 minute cruise is just sitting in line for the lock, waiting for the lock to fill or drain, and then exiting the lock. The commentary from the guide was ok, not great, but mostly interesting. The Chicago skyline is terrific ... and any boat ride on a nice day is a wonderful way to see any city, anywhere in the world.