After long discussion with a friend who lived in Hanoi, I decided to take the train to Phu Yen to join her and her friends on this trip.
I went to the Saigon Railway Station around 8:30pm to catch the train. I booked a hard seat and turned out it was a wrong choice. Even the train gave me a blanket and I used it as a bed sheet, the narrow width of the seat prevented me from a good night sleep. The guy next to me gave up his seat and stayed elsewhere. Other people had to sleep under seat or on the aisle.
It would take me about 12 hours to reach Tuy Hoa Station in Phu Yen Province.