Morgan is an awesome host and she has helped us a lot during our stay. She even agreed to pick us up on the airport! We've had such an amazing experience in San Francisco.
The apartment is on walking distance from Market Street, one of the many shopping areas in the city. If you don't have a car, you'll have to walk by many homeless hotspots to get there (unless you take the bus which is near the apartment).
For the people that do not have a car: get a unlimited bus card so you can quickly go everywhere.