Checking out transportation to the Phan Thiet / Mui Ne area from HCMC included the new rail 'service' to Phan Thiet.
The schedule is daily. Train SPST1 - Phan Thiet 14.00H >> HCMC 18.42H; train SPST2 - HCMC 06.50H >> Phan Thiet 11.20H; train SPST SPST3 - Phan Thiet 23.20H >> HCMC 04.56H. The cost is VND56,000. Seats are reserved, water is provided free and a trolley refreshment service is available. Seat spacing is an adequate 34 inches and the seats recline as much as an economy air seat does.
If you have a two-wheeled moto there is a freight car attached - for a fee - dependent on engine size. If you have large / excessive baggage (only a slim over head rack or under your feet is provided) you can NOT put it in the cavernous freight car! If you travel heavy, as this writer does, consider buying another seat (good for 3-4 backpacks).
If you see pictures of the train sets don't believe them. These units are well-worn double-decker units that have seen lots of service elsewhere. At least the air con works well. It is hard to believe the PT station is newly constructed - it looks as run down as SaiGon Station. It is just north of the River Cat Thi - about 400 metres from the Phan Thiet market square. GPS: 10N55.19 // 108E06.09.
Remember, Duong Sat (Road of Steel) is strictly on time - no late departures here.