How do you handle checking out of the hotels on the last day? What do you do with your bags--do you take them with you to Conference? Is there a place to keep them safe?
I can't speak for the Sheraton, but the Hilton has a luggage area where you can leave bags on day 3. It's a couple of bucks per bag, but it lets you check out in the morning and not have to haul bags around all day. There's also usually an area at McCormick Center, if you have to leave straight from there for the airport/train station/etc. Luggage is not allowed in the theater at McCormick, so you will have to check it someplace for part of the day. And the crowds walking around McCormick would appreciate it if you don't try to haul it around there other than taking it to the check-in area.