Last week myself and my family together with my brother-in-law's family (4 adults, 3 teenagers and one child) stayed at Villa Lavandina in Milna. The house itself was perfect for our group, with sufficient space for all our needs. A nice kitchen where we could prepare the meals we wanted, air-conditioned sleeping rooms (+ in the living room on the 2nd floor) with individual bathrooms, and several balconies with views of both the property itself and the surroundings including parts of the city of Milna. The hosts were very forthcoming and helpful, and contributed to that we had a great stay.
The outside area with a nice pool (including sun-beds and umbrellas), several seating areas (both by the pool and for dining outside, close to the kitchen) and garden allowed for enjoying good and lazy days by the house when we wanted to relax there. The neighborhood is quiet and the property is well shielded off (fences and hedges) to enjoy a good level of privacy.
At the same time, it is just a short walk from the villa and down to the center of Milna or to the "beach-area" (pebble or rocky beaches with crystal clear water) just outside the Milna center and harbor. Milna is a very nice city/village with what we felt like a really good and relaxed atmosphere with several nice restaurants/bars and small shops. There is a pharmacy, a bakery and a butcher (we only tried the bakery though, which was really nice) in addition to several small supermarkets in the city center where you can buy groceries. The selection is a bit limited in the supermarkets (they are all quite small), but you can still get most necessities there. We did some of our shopping there, but had also hired cars for our stay and chose to do most of our major shopping at the big supermarkets (Tommy's Hypermarket or Konzum) just outside the city center of Supetar (20 minutes drive from the house). There you can get whatever you need, and if you plan on preparing more advanced meals while staying in the villa it might be something to consider for others.
Milna has a lot to offer, so I guess it is not strictly required to have a car if you stay at Villa Lavandina (if you can get transported to/from the villa by other means), but it gave us the possibility to visit and see other parts of Brač (like the Zlatni Rat beach near Bol) which was nice for some "variation".
We really enjoyed our stay! One thing to note: The road down to Milna (from the house) is quite steep (good exercise though :-))