Highly depends on where in SJ<>SF you'll be, but over all I'd say it's pretty difficult for a few reasons:
- Caltrain currently terminates at 4th & King, not exactly a prime spot in SF, so you'll likely want to transfer to MUNI, so add that to your commute time and expense.
- The Caltrain ride itself is over an hour between SF/SJ.
- Caltrain lead times are't great outside of rush hour.
- I live in the middle of SF and it's 2hrs door to door to Diridon (SJ).
It isn't difficult if you're looking at the occasional trip to SF, but as a daily commute I would not recommend. I know quite a few people who do it and it's not pleasant spending that much time on a commute.
For a fuller picture, I think it's also important to consider taking the BART around the East Bay to Berryessa station. It can be better depending on where you're located.
To complete the picture, it's also unreliable schedule-wise. And it's in poor condition, your car might be insanely noisy (bring ear plugs), and bone jarring (give up on that one and move to another car.) For all that, it's not cheap either.
And the last trains are extra slow (so are all weekend trains) and not very late. So going to a club and then taking the train back home is not a good proposition.
- Caltrain currently terminates at 4th & King, not exactly a prime spot in SF, so you'll likely want to transfer to MUNI, so add that to your commute time and expense.
- The Caltrain ride itself is over an hour between SF/SJ.
- Caltrain lead times are't great outside of rush hour.
- I live in the middle of SF and it's 2hrs door to door to Diridon (SJ).
It isn't difficult if you're looking at the occasional trip to SF, but as a daily commute I would not recommend. I know quite a few people who do it and it's not pleasant spending that much time on a commute.