Can't think of a serious complaint
There's not much more you could ask for in a hotel; the staff was very friendly and helpful, the room and bathroom was both comfortable and clean and the location is perfect.
Location: Only a few blocks from the shopping hub on Michigan Ave with tons of great restaurants and bars on the way.
Dining: No complaints on my food or service whether it was calling for room service, having breakfast in the restaurant or grabbing a drink or cup of coffee at the bar. The staff is very friendly and attentive and my food was all very good. 
Room and Bathroom: Beds were very comfortable, bathroom and bedroom were both very clean. Not a lot of clothing storage space though- The closet has about 6 hangers and there is no drawer space so we had to live out of our suitcases (which for me, really wasnt an issue)
Spa: Great ambience and my massage was great. The steamroom at the end was the cherry on top.
Vertigo: The rooftop bar is spectacular; from the outdoor fire pit, views of the city, and the decor inside, everything was great about it. Again, friendly staff and great drinks, too!.
I can't think of a real complaint after my 4 day stay.