I've always wanted to try the bus but was never adventureous enough. This past trip a few weeks ago, I had extra time (or thought that I did), had a 10:40am flight home, so I took a taxi from my hotel in the gulch to the bus station. Then took the DIRECTO bus (I didn't know you have to request airport stop). Luckily I asked the driver if he stops at the airport, and I had a carry-on, so he knew I needed to stop.
Anyway, left my hotel at 8am. Got to the bus stop around 8:20. it was quick getting to the airport once out of the city, almost no traffic at 8:30am going out of SJ, so I got dropped off in front of the airport around 9am, and made it to the counter about 9:10. The Phucker asked his colleague what time it was and I just made it (even though I had a boarding pass in hand and no checked baggage--checked in online day before... WTF? 90 minutes and almost was not allowed on.)
So total travel time door to door about 1:10. Total cost was $3.
Would I do it again? Yes, but only if I had a small carry-on. I had a regular 20" roller carry-on and the aisle is too narrow so I had to carry it over people's heads. It reminded me of the scene from the movie "Airplane"
(LINK) where the stewardess carries a guitar and smacks each person in the head.
TIP: SIT CLOSE TO THE FRONT DOOR IF YOU HAVE A CARRY-ON.