I have been travelling a lot for work and holidays, and I have to say that this experience is probably at my top 10!
Great host, amazing location, the accommodation was fantastic and just perfect for a relaxing stay. The apartment has two floors with a lovely terrace where you can enjoy the sea view and an astonished moonlight. Roberta (the owner) didn't treat me only as a host but has part of her friends.
I've been invited to her place where I had the chance (twice) of having delicious food and knowing other local people and share experiences and thoughts about Ustica.
I would strongly recommend this accommodation, I am already thinking of my next stay.