Apartment itself: best location you can get in Oia, very clean, exactly as described and shown in the photos. Just a couple of minor things to note, which may or may not be issues depending on the person: 1. noise from water pump underground can be loud at night and a bit scary as we didn't know what it was in the first night. 2. could use a bigger hot water tank, had to space out showers a bit.

Service: Christo was very helpful and responsive from check in throughout to check out.
Would've been a 5-star experience for my parents and I; however, we experienced a theft incident in the apartment and lost 300 euros. We had 300 euros in an envelope inside the inner pocket of my Dad's purse, which was left in the apartment when we went to explore the town. When we came back, the envelope was gone, both the zipper of the purse and zipper of the inner pocket were open, both of which were closed when we left. We locked the apartment door and there was no sign of break-in, and we haven't lost anything else. The only possibility is that someone with the keys had come in the apartment and took the cash. We were really shocked and confused by this incident, which has caused my parents a lot of stress and ended our 17-day vacation on a very negative note as it happened on the last day.
I made Christo aware of this incident immediately and told him I suspect it's the cleaning ladies, who have keys to the apartment and came in the apartment earlier that day to refresh the apartment. He said he does not think it's them as they've been working for the company for 4 years. Regardless, from our perspective, we lost 300 euros to someone who had keys to the apartment.
I thought it's the right thing to do to write an honest review and mention this incident in the review, unless Thireon Houses wants to rectify the incident by compensating the 300 euros. I gave Thireon Houses the opportunity to consider the compensation and told them (5 days in advance of the expiry of the review period) that I would not mention the incident if it's already rectified. I did not force them to rectify it, but I just gave them the opportunity to. They chose not to do anything and said if I mention this in my review they will "take care of it" in their review of me. Nevertheless, I think it's the right thing to do to go ahead with providing my honest review.