My wife and I spent 3 nights at this place after having booked via hotels.com.

After the first night in a small "double" room on the 3rd floor with a window facing large air condition facilities on the roofs which were rather noisy we asked for a room with a proper double bed that wouldn't move apart during the night and a room with less noise.
For our 3rd night they found us another room. This time it was on the 2nd floor and had both a balcony and an entrance so a door between front door and our bed could be closed.
The extra door helped on noise heard from other guests on the halls but having a large window and balcony door facing the street and now being on the second floor made the third night in the Crystal Palace Hotel our worst night yet.

Walls are paper thin and there is an almost unbelievable amount of noise preventing a good nights sleep.
They have heavy wooden chairs that make an incredible amount of noise when dragged across the floor which seems to happen all around the hotel and is audible through-out all night long. Along with this came screaming water mains... One wonders how they had gotten the pipes in the hotel to make so much sound but whenever someone hit the shower or flushed nearby the pipes started a long and high pitched scream.

Anything below 4th floor is completely inhabitable as the noise from the most trafficked road along with sirens from passing by emergency vehicles and the train just across the street honking as it goes by.
The windows are even thinner than the walls and offer no dampening against the noise from outside the hotel.
After having had 3 awful nights in a double bed (that was 2 singles moved together as they don't have double beds according to the clerk) where the mattresses felt 20 years old and moved apart during the night we can honestly recommend steering free of Crystal Palace Hotel.

Hotels.com even states that all rooms have balconies and wireless internet. This is untrue. There is one PC on the 1st floor which requires a code which then lets you browse the web with a broken mouse that keeps jumping around on the screen.
Balconies are only for ca. half of the rooms and as mentioned above I would still steer clear of anything below 4th floor.