To make a long story short: 10 points!
Marta welcomed us very warmly, showed us the appartment - just as beautiful as in the pictures - and gave lots of recommendations where to go (bars, shopping, marktes ). The appartment is only 10 minutes walk from everything (Plaza Mayor, Plaza del Sol, Museo Reina Sofia...) and well furnished and really cosy - not a tipical holiday appartment. We were travelling in three and everybody of us could imagine to live in this appartment. We really felt "at home" and when leaving we felt kind of sad as we obviously had spent more time outside sightseeing than in the appartment. Next time in Madrid we definitely would return to this appartment!