We are a family of 4 and arrived on Serifos with blazing winds and because of that with delay. Korina nonetheless had us picked up from the port and awaited us in our appartment with some snacks. Great reception!
The appartment is simply furnished and definitely not too big for the 4 us. Two bedrooms, living annex kitchen and a small bathroom. Outside patio was great with a beautiful view overlooking the most beautiful beach on Serifos, but when there are strong winds you can not really sit outside. That was too bad.
The island is small but houses beautiful beaches and some must see spots like the monastry (amazing) and the capital Chora (beautiful). The port is tiny, but has some nice restaurants. The country-side is rough, no plants or threes and sometimes gives the impression you have landed on the moon. Great thing is that the island is not overcrowded with tourists.....we appreciated that a lot.
The stay at the appartment was nice, with amazing views. But, as said, if the winds start blowing, you now and then find yourself "locked up" in the appartment so if you come with kids bring some entertainment with you because there is nothing present in the appartment (tv, books, games).
Another important thing is that right after booking, rent a car. They run out of them quickly on the island and you really can not do without it; especially with kids. You could walk to the beach, but you need to be a bit of a hiker to do that every day. Korina helped us out with getting a car in the end and we are still thankful for that.
Tip we would have is that the kitchen could use a few more appliances like a toaster and electric water kettle.