The NH Calderon is Europe's version of the W or Ian Schrager hotels. It is very contemporary, very urban, and centrally located.
The rooms at the Calderon were spacious. The hardwood floors and the decor (navy blue and gold linens) could easily be someone's apartment. The bathrooms seemed a bit industrial.
If you choose to stay in the Calderon, please be aware that they do not provide irons or ironing boards in the rooms(you may want to confirm this) before you travel.