I came to Madrid for my studies and stayed at Pilar's place for the first 6 nights to look for a permanent accommodation. She was very nice and accommodating. The centre was very close and easy to reach even on foot and as I was looking for a flat in the area it was perfect. I can recommend Pilar's apartment for everyone who pays a visit to Madrid. You can have all the convenience in a calm apartment and amazing bathroom :)
Cheers,
Tamas