One of the worst Hilton's I have stayed in
Stayed here for the Chicago Marathon, as right near Grant Park. 
This is one of the worst hotels in this price range I have ever stayed in. The rooms are old and very stuffy. Ventilation is extremely poor and you cannot open the windows when facing internally as you have smell from the various kitchens below (deep fryers). The bed has two small sheets on either side of a filthy duvet and you can hear everything in the toilets next door. 
The room was only cleaned 2 of the 4 days I was there, and the other 2 it was cleaned after 19:00. The heating was broken and eventually fixed, etc etc. The cafe downstairs always had very long lines (10-15 mins) to buy a bottle of water.
Hotel is just too big to be managed properly (it seems) and just not good to stay.