Staying in a very quiet private room with bathroom in a wonderful historical building with elevator in one of the best neighbourhoods of Madrid, having almost every interesting spot within walking distance (e.g. the Prado and Reina Sofia museums) and getting lots of recommendations and a helping hand by very charming hosts whenever you need it - what else can you ask for?
I had a wonderful stay and will keep Madrid in good memory! Thanks to Angel and Nacho!