Agree with the BART-to-SF recommendation. You can take the AirTrain direct from the terminals to the SFO BART Station.
Also, regarding the RCC thread, IMO the RCC in the international terminal is FAR better than the one in Terminal 3. These terminals are connected plane-side of the security checkpoints, just turn left after security in Terminal 3. Disclaimer: I don't know if the RCC in the International Terminal functions differently than the domestic one as far as day-passes, etc.