On the road with sleeper bus is comfortable. I recommend to take the sleeper bus for a long trip if you are travelling around Vietnam, I mean an overnight bus trip. It may cost a few bucks more than the normal A/C bus but its worth it.
THE GOOD OF BEING IN A SLEEPER BUS
They gave you a blanket to use for overnight, seats are reclining(that makes it comfortable at night), a free small bottle of water, and it has toilet. Find the real SINH CAFE, they have offices on every town. They usually do the open tour sleeper bus for $35 USD/pax from Hanoi to Saigon. Stopping on different town destinations along the way which you can stay for a few days and just confirm your ticket to their office whenever you want to go. Make sure you go to the real SINH CAFE to avoid scams.
“Avoid scams, look up the real SINH CAFE! Don’t take sleeper bus on border crossing, only to travel within Vietnam.”
Only if you are travelling within Vietnam! Don’t take sleeper bus when border crossing, it’s a disaster!!! They will put you in a sleeper bus until the nearest town to the border in the middle of the night and leave you there until morning, a local A/C bus will fetch you and that will be your bus to your destination to the next country. It sounds unbelievable but it happened to me!!! Waaaaaaaaaaaaa!!! Just want to share this to avoid terrible experiences travelling.