I plan to do a border run to VN in a couple of months, I usually go Thailand but it seems they're getting stricter by the day, given I have no VN stamps/visas in my passport I shouldn't have any trouble with it? My main concern is getting a bus back once I come back over. Whenever I went to the Koh Kong border to Thailand, even if I left PP at 7am, by the time I came back through Cambodian immigration all the buses had left for the day and as I really didn't want to have to stay the night I shared a taxi with some random locals (I've done that twice now). Does anyone know if buses would run from the Vietnam Border (Not sure what the place is called?) after say 3pm? If not would there be shared taxis available? Also how long is the journey from PP to the border to VN and the name of of the place?

Here is what an agent told me, relative to using the Bavet checkpoint (border with Vietnam):
"You can buy ticket depart from PNH at 7am and you arrive border around 11am. And you can return ticket depart SGN at 1pm, and bus will arrive boder around 3pm. There is also a 3pm depart from Ho Chi Minh. 1pm is Bus, 3pm is VIP Van. Mekong Express bus, 12$/way for big bus and 15$/way for VIP Van
If you want to go SGN and back same day, not possible for big bus."

Basically, it is 3-4h to Bavet. I'll let you know what I learn about taxi leaving from Olympic.