Great flat with a bit of a luxury feel. Great position. Ideal for a long weekend with friends in Madrid. Easy communication with landlord. Easy check in and check out. Kitchen is fully functional and there were even some spices and oil.
Downside is that it's very noisy at night. I assume that would be the same for most flats that are so central. Bring ear plugs if you want to go to sleep before 4 am.