I spent 7 nights at CQ Wacker. The room was small but sufficient for my needs. I was out sightseeing most of the time, so a bed and shower were all I needed, and both of these were excellent. The bed was extremely comfortable (I slept really well all week, and I don't often do that in my own bed at home). The shower had plenty of hot water and pressure, and the adjustable/removable shower head was a big plus. When I checked in, I asked for and got a room with a view of the Chicago River, with the caveat that the room did not have a microwave or refrigerator -- neither of which I ever use anyway when I'm in a hotel.
The biggest plus was the location -- the hotel is smack-dab in the middle of everything I wanted to see and do, and was within a few minutes' walking distance of all CTA transit options, tons of restaurants, live music, shopping, and right across the street from the River Walk. And with all the inexpensive and so-worth-it multi-day transit pass options, I was able to do an entire week of sightseeing from one end of the city to the other without ever getting in a car. Getting to CQ from O'Hare is an easy train right and a 7 minute walk to the hotel.
Overall, the CQ location and experience was an excellent choice for my Chicago trip, and I would definitely stay there again.