My boyfriend and I travelled from Rome by train to Casa Formosina and the apartment was perfect! It was easy to get to from the train station (just a vaporetto and a short walk). A lovely lady called Ruby was waiting for us on arrival to show us to the apartment and advise us on how everything works.
The apartment itself was as described small but perfectly comfortable and in a fabulous location, everything really is at your doorstep. There is excellent wifi, a lovely modern bathroom and a well equipped kitchen.
On the day of our departure Andrea very kindly extended our checkout as our flight was not until late evening. I would have no problem recommending this apartment to any friends or family visiting venice.