I only stayed here for a night but the place seemed to be in a good location on a quiet street but close to restaurants, public transport, and sights. The beds were the most comfortable we have had in the 1 month of our trip. We found red hair on one of the sheets (that wasn't ours) but otherwise, the place was clean and comfortable. The only downside was the check-in process, it took a while to get the access codes to the entryway and apartment after we filled out the paperwork. This was the only stressful part of the process as we had small kids who were tired and had to wait at the door while I tried to contact the host.
I would book again if I was in Porto again.