Existing passenger train service in the Bay Area is a ridiculous mess, with BART, Caltrain, ACE, Amtrak, VTA all run by different entities. It's a total disgrace. Unsynchronized, disconnected, few good ways to transfer from one to the other, and schedules that don't make sense. I tried commuting on ACE, their trains are pretty nice (WiFi!), but their LAST evening train leaves San Jose at 6:38 PM, which you'd know is useless if you've ever worked at a tech company.
We need expanded and coordinated schedules, trains that actually connect in sensible ways, and a ton more tracks, which is just not going to happen. Look how difficult it is to get BART extended anywhere.