The appartment is perfectly located in front of the sea, very well decorated as shown in the photos. It has everything you need to cook and to relax at home. It's also 5 minutes away from the train station, but no problem at all for sleep.
Regarding Mariella, she's always ready to help. One of the best hosts I've met in my airbnb experience.
About Santo Stefano, is a small beautiful town with bars and restaurants.
I definetly recommend the appartment and the area with almost private beaches.