Yeah SAN is pretty inconvenient. The bus ride is long, just like LAS, even though the facility doesn’t seem that far.
SFO can be a pain when returning. You’ve gotta go down to the ground floor, then back up to the platform to catch the train. If you’re catching UA from Terminal 3, it can be a long ride.
I like PHX now. That train zips through the airport like a torpedo and then drops you off and picks you up on the same level as the car counters.