I liked the CAF tour, but it had some slow parts. I thought it was maybe 20 min too long. Still, it's interesting. But we really had a blast on the Duck Tour (if you have kids).

We took the Chicago Architecture Foundation's River Cruise on 8/23. As others have mentioned - it's 1.5 hours, but thoroughly entertaining. We took an 11 AM cruise and got a bit more sun than I would have liked, but you won't have that problem in October. Our photos and video clips are awesome. Enjoy!