We stayed at Joao's place for our first visit to Lisbon.
The communication from Joao and from her cousin, Ines, was excellent - before and during our stay.
The apartment is very well located for supermarket, restaurants and transportation - as well as for local attractions. Our 4 yr old son was particularly impressed that we lived next door to a superb ice-cream parlour. Santelmo restaurant (around the corner) is also particularly noteworthy.
Joao's apartment is clean and really well-presented - exactly as the description on airbnb. The road can be a little noisy but it did not detract in any way from our enjoyment of staying there. We would not hesitate to recommend Joao's apartment.