My mum and I stayed at Silvia's apartment for two nights on our short visit to Florence and it was great! The apartment was a short walk from the train station and not far from the main sights including the cathedral.
Silvia was wonderful and met us on our arrival and showed is the ins and outs of the apartment which was exactly like the pictures. The only thing we would point out is that there is no lift and a 60 stair climb as Silvia has described. We did count the stairs too. This was not a problem for us but something to take note of if stairs are a problem and you have lots of heavy luggage.
I stayed on the sofa bed which was very comfortable and my mum has advised that the main bed was comfortable too! It was also very handy to have a kitchen available to cook up a quick meal after a long, exhausting day of sightseeing.
I would certinally recommended Silvia's place to my family and friends visitng Florence and I would certinally stay at Silvia's again when I return.