Pensão Rosinha has a great location, it's only a few minutes away from Bairro Alto (the going-out area in the centre) but is on a quiet street. There is a park nearby, small coffee shops, very friendly environment overall. The view is also very nice from the kitchen and some other rooms that have windows.
The Airbnb works like a hostel, which me and my friend liked very much because we met a lot of great people. The disadvantage of this is that you hear doors cracking and all conversations through the walls.
Paulo and Camila are super friendly, they gave us some maps and tips and they come around almost every day to check up on the flat.
Overall it's a very lively place with a lot of cool people (if you're lucky) and Lisbon definitely became one of my favorite cities so far!