We stayed 4 nights in Luis apartment.
We loved the place and the tastefull decoration. The apartment is well equiped, very comfortable and ultra clean. The balcony is a real plus : very sunny deck all day long and nice backyard view.
Luis is a very reactive and nice guy, ready to help and give some good advice. He definitely knows perfectly well Porto.
The apartment is situated in a very trendy area, full of art galleries. The advantage is definitely to be close enough from the city center and places to hang out but in a peaceful and calm area as well.
No hesitation at all if you plan a trip to Porto.