The house is just perfect for a family stay (we have been there with our 3 young kids): plenty of space (with 2 large rooms and a large living room), very well equipped (especially in the kitchen) and 2 large terraces which are perfect for breakfast and dinner.
Vassileos is very welcoming and available.
The location is very nice, close to many shops and restaurants. The beach is just a few minutes walk (not the best beach of Serifos, but nice enough) and Livadakia beach is about 15 minutes walk. All the nice places of Serifos are easily reachable by car.
Only small drawback is the bathroom (not very convenient) and the parking (no private parking, so you have to park in a public space and it is sometimes difficult to find available space)
Despite this we highly recommand to stay here!