1.5" Cockroach in room
My experience with housekeeping in the hotel was terrible. On the first day, I left a tip of USD 5 - it was not there when I came back (as expected), but the room was left exactly the same way as I left. She has not even folded towels or made the bed.
On the second day I have found a cockroach of about 1.5 inches walking on the wall. It was the most disgusting experience I have ever had in a hotel. As the windows could not be opened, definitely it was a cleaning problem. I went to the front desk to make a complaint - the manager in charge gave me a discount (50 dollars, I have understood it would be 50%) and a breakfast. Nevertheless, I have not received any voucher and when I wake up the bill was already under my door (without any breakfast credit). So I took my breakfast at Starbucks. 
I have already stayed at this hotel before and in other Radissons. If everything was fine, it would be difficult to say this hotel is really a Radisson - but this time my stay exceeded the worst expectations I could ever had...