The appartement is nice, very clean, and very well located. The host was really kind, giving us a lot of suggestions of restaurants and bars, that we appreciated.
However, we were disappointed with the danalock system that didn't work at the entrance door. Having to call the reception (available 24/7) each time we wanted to enter was not very pleasant... this system is really not working well.
Moreover, we had to wait 1h30 before having access to the flat when we arrived because of cleaning issues. But the host was always reachable and communicated with us.
All in all we would still recommend this appartment for a nice stay in Porto !