The SFO shared facility is ridiculous. I've used it a few times but the last time it took almost one full hour to get from the terminal to the building. Problem is that the bus has to go out onto the 101 and if there is traffic you get stuck in it, as we did. And the $5 fee adds to the insult.
Apparently, the shared facility is built so that once the airport is completely re done there will be an efficient train connection.
I guess we'll all have to wait till then.