The hotel is slightly tricky to find unless you're very familiar with the airport. I went to T5 arrivals level where there is one sign near the tube exit and UK arrivals though you still have to go up one floor in the lift and then follow the walkway round.
Not checking in until quite late at night, I really appreciated being within walking distance of the terminal and not having to worry about shuttle buses etc.
The hotel has a stunning, ultra modern design with shops etc. along the central walkway. Breakfast on the ground floor was also extensive and high quality.