We are traveling to San Francisco in September 18-22. My husband is attending a conference at the convention center near 3rd and. 4th and Mission? I really rather not stay at a big pricey mega hotel near there. Where is a good area to stay close to public transportation that will easily get him to convention and an area that will be conducive for my own explorations while he is away. I would like to stay within the city and open to vacation rentals etc... Your advice is appreciated.