- 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.
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.
Beijing wasn’t much different before they went crazy on subways, but you could pad your endpoints with cheap taxi rides.
https://www.caltrain.com/projects/electrification/project-benefits/caltrain-electrified-service-plan
Most of the stations will get faster with more frequent service. I think the electric EMUs also means the ancient clunker ones will be gone.The difference on the express service is much less (65+ mins to "under an hour"), presumably since the trains can spend more time at or close to top speed due to longer distances between stops.
[0] You can see a list of stations and mile markers here: https://en.wikipedia.org/wiki/List_of_Caltrain_stations
A quick search shows SF to SJ to be 1hr to 1hr 23 mins but then you'll likely need 20-30 mins at each end to get where you're going.