A beautiful suite, great views--too bad about the elevators
My partner and I stayed 3 nights in a suite while we visited Chicago over a weekend. The service, from calling the Four Seasons to book the room, to arriving and being welcomed as we stepped out of our cab, through out entire stay was very, very good. I was especially impressed with one of the concierges (I think her name was Michelle), was exceedingly helpful and very informed on every topic about which we spoke to her. 
Our rooms (sitting room and bedroom) in a corner of the 34th floor were lovely and the views of downtown Chicago (I chose a "city view" room because we'd never been to the city before) were great. We were far away from the elevator and never heard any noises from the hallway, which is great. 
The one complaint I have about this particular hotel are the elevators; to get into the hotel from either the ground floor or the adjoining mall you have to take one elevator (there is a bank for 4 of them) to the lobby. From the lobby you need to walk through several rooms to get to a second bank of elevators (again, there are 4) to get up to your room. This wouldn't be a problem if you weren't coming in and out of the hotel many times in one day, but we did just that--for example, we'd eat and shop in the adjoining mall and then come back to our room to drop off bags and get our coats before going outside. Taking the two elevators wasn't too annoying if the hotel was quiet, but if we happened to need an elevator at a busy time (e.g., late morning on a weekend), we'd be waiting for up to 10 minutes to get on an elevator with enough space to fit 2 more people. Then we'd have to go and wait for a 2nd elevator to complete our trip! I can't imagine trying to do that with a stroller or a wheelchair---that would just be too frustrating at a busy time.
However, aside from the elevator challenges, the Four Seasons Chicago is a very nice hotel and I was so pleased with the staff there. I'd definitely consider staying there again--though I'd plan my days a bit differently to avoid having to use the elevators any more than absolutely necessary!