We really enjoyed our stay in Nelson & Lucia's flat. Yes, it is tiny but exactly the size you need for few days in Lisbon. Yes, it is a bit noisy street in the evening/first part of night but it is really close to subway, harbour and still in a walking distance to city centre. There were definitely more pros than cons for us.
Lucia was very helpful and her advice on what to see and do in Lisbon was very welcome.