Not really. The platform-to-platform time from LA to SF is going to be, at best, a little less than three hours. That's comparable to the time it takes to fly f

Not really. The platform-to-platform time from LA to SF is going to be, at best, a little less than three hours. That's comparable to the time it takes to fly from LAX to SFO plus the ~30 minute BART ride to downtown SF. LA is so spread out that departing from LAX or Union Station doesn't make a big difference. Most people are going to have to fight traffic to get to either location.