After searching and reading old postings about apartment rentals in Madrid, I emailed Homelidays.com and they responded with this one:
El apartamento Mayor (38340) for 900 euros for up to 6 persons for 6 days.

As I look at the apt I wonder how 6 people can be acommodated and I also wonder about the facilities and my money worth.

Have you rented from Homeholidays? If so, what is your experience?

Any other apartment or company you recommend will be highly welcomed.

Thanks