I stayed in Shirin's place for 4 days and everything was perfect :)
She is a great host!
I had some techinical problem with the booking at the beginning, but Shirin patiently waited for me keeping the room booked.
She suggested me several places in the neighborhood for eating, really good spots!
The room is exactly as described: big, cozy and clean. Moreover, Shirin provides also some useful amenities in the room, such as hairdryer, electric iron and lot of space for clothes.
The house is not very big, but it's exactly as the mission-street-style. In less than 20 minutes (10 walking,if you want, + 10 of bart) you are in the centre, thus it's a perfect place for travelers, as advertised.
I definitely suggest Shirin's place :)