We were unable to travel at the last minute, but our friends stayed at Petros's place in the Plaka and loved it. Here's what they said:
The location of the Plaka apartment is perfect, it's a little out of the city center, so it's quiet, but still a very short walk to everything. The town of Plaka is so beautiful and a laid back, a perfect place to base a trip to Milos. Our host was super nice and went above and beyond to help us out and make us feel welcome. He even went out and bought a charging cord for our phones when we were having a problem.