Mercedes is fantastic host, she made great recommendations for all our special needs (antique bookshops and markets). You can trust her opinion regarding food and markets as it was all outstanding.
The studio is situated in the best district in Madrid for living (save and quiet), just across the street from Retiro park. It is very clean and perfectly equipped with all you might need. I already wish to go back :) and definitely recommend both Mercedes as host and her lovely studio.