Poor customer service, dirty room, felt unwelcome
Came to Chicago for Labor day weekend and we have stayed at a Westin in several other cities and always had a pleasant experience. This time however was anything but enjoyable. 
Our flight got in very early---about 8 am and I had called the previous two nights about an early check in. I was assured that it wouldn't be a problem as the hotel was no where near capacity. When we arrived however, it was an entirely different story. We approached the front desk and gave our name. The woman at the desk had a smug, unhappy attitude from the get go. After informing her I had spoken with the night manager about early check-in, her attitude got even worse, which I didn't think was possible. She informed me that our room "wasn't ready" and that we needed to check back in a couple hours. When I expressed again that I had confirmed with a manager an early check-in, she immediately became combative and told me I could call Starwood Hotels and report them if I felt the need. This came out of no where and we decided to give it some time and wait for the phone call they promised. 
Two hours passed and we never heard anything from them. We returned to the hotel and politely asked again about getting into our room as we had plans for a Cubs game at 1 o'clock. Again the same associate was inconsiderate and actually just walked away at one point for several minutes without saying anything. When she returned she told us she "found" a room and that in the future we needed to be more patient. 
After that experience, we figured our struggles were in the past. I was wrong. The next morning we awoke and left the hotel early in the morning and did not return until almost 7 in the evening, only to come back to a room that had not been cleaned. We did NOT leave a do not disturb hanger on the door. Our bed was unmade, our trash was not emptied and our towels were not replaced. Even worse, we noticed not just one, but several stains on our bed sheets. I had to go fetch new towels and it was not a good feeling sleeping in a dirty bed. Knowing that we paid almost $300 a night for our room started to put a bitter taste in my mouth. 
On Saturday morning, my girlfriend had an hour long massage scheduled in the spa at the hotel---one she had looked forward to for quite some time. When she arrived at the spa, they escorted her to the back and she prepared for her massage only to have the masseuse show up 25 minutes late. We were not in any time crunch, so she was perfectly fine with it, but when the masseuse cut the massage short after 35 minutes and told her she had to get to her next appointment, my girlfriend became disappointed. She was given a gift card for her troubles, but the spa was booked the rest of the weekend so it proved to be worthless during the rest of our stay. 
I'm not one to complain and I have actually worked in the hospitality industry for many years, but this was by far the worst hotel experience I've ever had top to bottom. Checking in was a nightmare, getting our room cleaned proved to be a challenge and the staff was all around unfriendly. I would never consider returning to this hotel nor would I advise anyone else to stay there.