Salvador's apartment is very comfortable and spacious. We stayed with two for almost a week and it was a great stay as part of our Portugal roadtrip by car. It is located in Belem in a quiet neighbourhood where is not to do a lot on itself, so you need to take into account the commute if you want to reach other downtown neighbourhoods but with nearby public transport that is easy to do.
Don't expect parking in front of your door as the streets are busy but no problem to find a spot a 5 min walk away.
Salvador is a great host, very responsive during our stay via Whatsapp and pro-active in checking our possible needs.