Fine stay, but room for improvement
The Omni Chicago has a wealth of offerings to recommend it: unbeatable downtown location, a relaxing and sophisticated atmosphere, comfortable accommodations, and a staff that understands hospitality. If I were considering only my room and the foregoing, it would rate 4.5 stars. However, there were a few unexpected annoyances whose combined effect had me doubting I'd return. To wit: 
. a somewhat awkward check-in on the third floor instead of street level. I can't imagine most of us like having to schlep luggage down a hallway and up an elevator *before checking in*
. far too few elevators for a tower of this height, thus constant waits/packed cars at most times of day (both sets: street>3, and 3>penthouse)
. a vintage bathroom wall phone, positioned such that you couldn't avoid knocking it off the hook -- then had the tedious job of hanging it back up, always right out of the shower
. a family/pet-friendly atmosphere that was occasionally overwhelming: dogs loose in the hallways, noisy children everywhere, double-wide strollers blocking every conceivable doorway. I know, none of this is the hotel's fault -- but if you're courting that demographic, you need to have a plan in place to control it. 
. poor hallway acoustics that magnified the endless sounds of slamming doors and screaming children
In sum, I reiterate that the Omni is a fine property in a great location with top-notch staff. But I'd prefer to leave the Ugly American chaos of Michigan Avenue outside my hotel. That's difficult to do here.