We had a great stay at Echoes and our host was as helpful as it gets. The view is the best, its super quiet, and you can enjoy cooking a quick meal in the outside kitchen.
Antonis provides a nice range of local items in the fridge including yogurt, honey, jam, peanut butter, orange juice, milk, bottle of water, and a fresh fruit basket. Bread is also delivered in the morning. It will also still be a good idea to shop in advance for cooking or snacking, but if you haven't, you can do that while driving a little adventure through the beautiful narrow dirt and paved mountain roads which provide spectacular views of Milos.
In regards to driving, get the smallest car you can find to make it easier for you and for other drivers. I had a rental Nissan Micra and it had no trouble going up the little mountain roads.
All in all, this is a unique experience. If that's what you're after, you'll enjoy Milos and Echoes.