Stayed at Skalvos' studio for 9 days. Very well located. Magnificent view of the sunset and the caldera. On the hiking path to Oia. Very close to Firostefani bus stop and at walking distance from Fira bus station (which takes you everywhere). Host was available and always replied promptly, which I always appreciate. Apartment identical to the pics. Very clean, lots of hot water, modern bathroom, functional WiFi and markets close by. Housekeeper was very nice and helpful in providing info on the island and what to do. Much quieter when the villa next door is vacant. Since both apartments share a rather small enclosed terrace, it became very noisy when uncivilized guests arrived. At 2 am, after having heard door slamming and loud talking for more than 3 hours, I had to go out and ask them to keep it down. The next guests were quieter but smoking. At that point, I emailed the host who was very receptive. As well, there is the sound of a motor (pump I believe) which, although slightly annoying, was interfering with my sleep when it went off every 10 seconds for hours on end in the middle of the night when the uncivilized guests were next door.
All in all, even though noisier than what I had expected or hoped, I would recommend Sklavos' studio since the host was very receptive and successful in solving the situation.
But for the noise and smoking, I would have rated the studio 5.