We stayed 2 months at Quique's apartment! It was a great place to stay, very comfortable and in one of the best zones to get to know all of Valencia's main neighborhoods and attractions.
If you are staying long, my only two observations would be to double check with Quique if the heating on the living room was installed as it might get pretty cold. Also, if you are traveling with other people, take on account that there is are long stairs up to the apartment and within the apartment to the rooms.
Other than that, Quique is an excellent host and will respond fast and try to make sure you have a great stay. We would totally repeat staying at Quique's.