I cannot express myself emphatically enough about how wonderful it is to not have to rely on a car. I've saved so much money and headache, and it's been such a freeing experience, I don't know if I could ever go back to having even a short driving commute.
SF may be easier to get along without a car, but I don't find SV particularly difficult. Some combination of Caltrain + Zipcar + Uber + taxi + bus + bike + short walks is always available.
Is that enough to make the city more attractive? Isn't office space cheaper in MV or PA?
That said I'm super happy with workout out of the mission near the 24th street bart. And it's very affordable.
Housing is phenomenally more expensive, especially when compared to MV or Sunnyvale.