Madrid is a great place to live, mainly because it is a capital city with all you need, and with the quality of life you do not have in London or Paris: no pressure, no insecurity, you can eat out for as much as 10 €, people are open and talkative.
However, you have to know that the typical Madrid flat does not comply with the expectations 90% of newly arrived expats.
Plainly put, the average quality of real estate in Madrid (and in other main Spanish cities) is significantly below the average quality in other big cities, and especially the USA.
This means that even with the crisis, there is more demand than offer for quality, premium or luxury flats a bit like the photo at the start of this post.
At any time, you will only have handful of real luxury flats available in Madrid, which you have to know where to find and how to book. If they let you book months in advance, because usually the companies managing these flats just accept booking a month before the entry date.