I Highly recommend the place :
don't get confused by the price, you get much more than you can expect from this type of price. I'm a frequent airbnb user, and it's one of the best bedrooms I've ever stayed at.
LOCATION : the flat is located not far from downtown so even if you've got to take the tube, it's ok. From there don't bother to take the metro to go to the airport, if you take a taxi it's around 8 euros. An from Maria's to Praça do Comercio 11 euros. If you use the subway and stop at Praça de Espanha prepare to have a 10 min walk.
Maria street doesn't have traffic during the day, so it has even less during the nights. The building is calm inside.
BEDROOM : if you're accostumed to airbnb, you feel immediately well at Maria's and Carlos'. It's super clean, the bed is really good, you've got aircon, curtains AND light shutters (which doesn't go often with all bedrooms). As the bedroom looks at the rear of the building you don't have noise. Also, Maria and Carlos spend much of their time in the other part of the appartment, so it makes you have a good feeling of privacy.
BATHROOM : as the rest of Maria's flat, everything is clean.
HOSTS : Maria and Carlos are very reliable persons, communication 100% ok. When you check in Maria tells you the rules of the flat (which is ok) and helps you feel at home. You can speak with Maria she has strong communication skills and makes you feel you've already known her for years...
I whish mosts of airbnb hosts were like her.
Value for money is 100% !