I find it hard to call this a 5-star hotel. It feels old, the furniture is heavy and outdated, one of two elevators wasn't working throughout our stay (causing long waits for the other elevator), and most importantly - service is far from being at a 5-star level. The guy who checked us in was very grumpy and unfriendly, and on another night - the lady at the reception kept us waiting for over 5 minutes while having a casual chitchat with a friend. (there were, however, very nice receptionists at other times).
It's important to be aware of the high hidden fees at this hotel. It advertises competitive prices, but only when you check in, you realize that they charge 80 zloty (20$) as a daily parking fee, while most other parking lots in the city charge only 20-30 zloty per day. With such an extra 15-20% to the room price, their prices are not that competitive any more...