I stayed at the Nostos apartments closest to St. George's beach that was hosted by Stavros' mother Sandy. The hotel is about a 10-15 minute walk from the port but I arrived late in the evening and decided to take a taxi (paid EUR 10). I really liked the location. It was central and somewhat tucked in a quiet street, but it was easily accessible and walkable to the center of town, beach, old market / castle neighborhood, port, and bus station.
Sandy was very kind and made sure my stay was comfortable. She was always available to answer questions, showed me around and pointed out places in the area. I enjoyed my time in Naxos and at Nostos so much that I ended up extending my stay for another two nights. Stavros was very responsive and was able to accommodate my request promptly.
Also it was convenient having a kitchenette for making coffee or light meals, and the balcony had a nice view and seating. I would come back and stay here again!