Location is great. Just in the center, near evrything. We visited the whole city by foot. We just took bus to go to Seralves and Casa da musica. Appartment is large and just as described. If it's important for you, you should know that appartment is in an old building (as all the city center). So, it is not well isloated and it could be noisy because of the street or he neighbours. We stayed in winter and it rained a lot, heating system is not smart, but it was just sufficient.
Cesar is nice. It's easy to contact him and to meet him as he runs the wine bar just under the appartment.
We recommend it.