Michaela is a great host!
She answered almost immediately to every question or request.
She also sent a very friendly friend of here to show us the place.
The apartment's location is perfect - a small street with local restaurants and bars.
As people already wrote, apartment is at 4th floor, and there is a bad cigarette smell when you climb up the stairs (I assume there is one heavy smoker neighbor).
since it is an old building, the wooden floor is a bit squeaky, and the place was a bit cold (even with the electric heaters that works fine).
Hot water works with gas, so you need to turn it on before shower and turn it off when done, which was a bit annoying, since it is not turning off automatically, and dangerous to leave it working if not in use.
Bed was extremely comfortable.
On our last night (we booked 4 nights), there was some kind of a party on the street/one of the bars, and it was very noisy for light sleepers like myself, until 01:30.
Lisbon is great. BTW.