Rye, Robin, and Olive have a really nice listing. The house is kept in great order, the private bathroom was great, and the access to the kitchen was nice.
The only thing I'd caution visitors about is the neighborhood. The listing is not lying when it says there are a large number of homeless people in the area. We heard people most nights at all hours of the morning. Our car also got vandalized (which we believe is a rare occurrence).
The mission has some of the best food in San Fran though and I'd be hard pressed to find better more knowledgeable hosts on this site. If a little character and culture is what you're after, you won't find a better listing in San Fran.