The brief version. We liked this place a lot. The location is perfect, it was clean and comfortable, the hosts were very nice, and the AC works. You need to be able to climb 6 flights of stairs (3 floors). We would stay there again.
Important: the apartment is in the middle of a UNESCO heritage zone. Staying here is the right decision to keep the zone occupied and funded. In addition to being thoroughly delightful.
More comments: we have stayed at many types of AirBnBs. Some are mansions, and I feel a little uncomfortable in them. Mansions are not homey. Jovita's and Francisco's “Green House” is more like the kind of place I would like to have in the city … comfortable, simple, and restful.
The most important thing about this property is the location. The neighborhood architecture is classic. There are restaurants, shops, and cafes nearby. It is a 5 minute walk from Sao Bento station - you don't want to be closer OR farther. Its elevation is halfway up (or down) the elevation of the Porto hills. That way you only have half the climb coming and going. Ubers abound, and the streetcar runs right by the door. You are 15 minutes from the river shore. The UNESCO issue is important … the Portuguese need us to support their old town more than whatever hotel on the outskirts does.
Jovita was on a retreat when we were there but her communication was excellent - better than mine because I was having phone problems with the AirBnB app. Francisco ran down to greet us and took our bags despite our feeble protests. The AC was lovely, but we stepped out on the balcony and leaned over the street. Francisco gave us a great orientation to the property and neighborhood.
We felt safe the whole time. We didn't use the kitchen much but it had every thing we needed. We slept on the main floor, but during any month but August might have taken the loft.