This place is a great way to see Madrid cheaply!! I recommend staying with Gabriela completely!
Her place is clean and small, just enough for a pair of travellers to stay at. The bed and room are both clean and functional, bathroom to boot.
I recommend taking the 24 bus to her place, as the metro has a 15 minute walk which can be a little tiring with all your baggage.
Great place, great host, great experience!