We had a problem with the apartment upon arrival and weren't able to reach David - his parents did help us out but it was a bit difficult with the language barrier. The apartment we ended up in is on the second floor of the house: small, older and good for a few nights at most.
The apartment is in a good location - perfect spot for those interested in Bairro Alto and also pretty close (~10 min. walk) to a metro stop. While the neighborhood looks unsafe when you arrive, it's totally safe and calm and there are many great eateries/bars in the area. Would recommend for a couple looking to spend most of their time exploring and use the apartment mostly for breakfast/sleeping.