I stayed at Vaios's place in Pollonia for 5 nights. It was brilliant. The location is perfect - a short walk to the centre of town and very close to the shore. It is also situated on a quiet street so it feels 'local' and non-touristy. The room was spotlessly clean and beautifully furnished with excellent air con and wifi (the bed was also comfortable and big!).
Vaios is an absolute gentleman; he was so generous with tips on where to eat and what to see around Milos. He was also very accommodating when it came to arrivals/departure. If you're visiting Milos, you should definitely stay here!