Sofia's boutique hotels are great and pretty close to Oia. I'd recommend this place to others, just that the air conditioner was a little noisy but we didn't have any issues. I've removed a star because we checked in pretty late since our ferry was missed and we had to arrive by the only option available to us. Although Sofia helped us check-in in the middle of the night and we appreciate that, she seemed paranoid about the check-out and kept on asking us to check-out before the actual check-out time. We had to firmly respond to her that we won't check-out before noon (which was the original check-out time). That was quite unpleasant but apart from that, our stay was ok.
If you have check-in bags/luggage, I'd not recommend this place since they don't have any helpers with the luggage and her hotel is quite a bit of a walk from the parking space!
Good luck.