Upper floors are too hot, in hot weather unbearably so. I stayed on the 16th floor. The outside facing walls and windows act like radiators. The room was uninhabitable during the day and barely stand-able at night. I kept the door to the corridor wedged open to try to create a draft.
During less hot days the rooms were also hot as the heat rises up the building from the lower floors. Men working on the 16th floor advised me that the upper floors were stuffy and uncomfortable in December from rising heat. For this reason I would not book Chapter again as you have no control as to which room you are allocated. I complained during my stay but was not moved. The views from the windows whilst spectacular do not sufficiently compensate.
Apart from the heat the accommodation is good. I stayed when the building was relatively empty. The common areas were comfortable to relax in, the area central, and the staff without exception excellent.