we want to know if we do not plan to have any stops between the two cities, how many hours is the least possible travel time? Is is better to take a train or sleeper bus? what is the price difference?
thanks
we want to know if we do not plan to have any stops between the two cities, how many hours is the least possible travel time? Is is better to take a train or sleeper bus? what is the price difference?
thanks

IMO it's best to take a sleeper train, soft sleeper, to Saigon.
Check here:
Much safer and more comfortable than on any bus, day or night. Even if it is more expensive.
As above, cheap to fly, even cheaper if you fly out of DAD (DaNang) just south of Hue. But, if the choice is bus or train, then TRAIN for sure. Yes it costs more, but well worth it.

It's actually a 2+ hour drive between Hue and Da Nang and in my experience the flight from Hue to SaiGon costs the same as the flight from Da Nang to Saigon (I have flown in and out of Da Nang only twice when Hue airport was closed for a month earlier this year). So I don't agree with #4 as it adds time and costs getting from Hue to Da Nang airport. The flights are cheap and the earlier you book the cheaper the fare. Often I have found the earlier flights to be cheaper and that means getting to the airport very early. It's about a 20 minute trip to the Hue airport from the centre of Hue.
Between Hanoi and Da Nang there are more comfortable carriages but from Da Nang south to HCMC the carriages are pretty basic. The SE1, SE3 and SE5 all leave Hue in the morning and reach Sai Gon the next morning between 4 and 5 am, which is usually not a convenient time to check into a hotel. The SE7 leaves Hue at 19:07 and reaches Sai Gon at 15:45. It takes longer than the other trains as it makes more stops.
I would never consider going from Hue to HCMC by the overnight bus - or any bus really.
maureenm, actually I was thinking that leaving from DAD would give the option of flying JetStar, and maybe taking the "over the top" route from Hue to DaNang, for the great scenery.
I do see that JetStar is now flying out of HUI too, but their fares to SGN are lower out of DAD, 490,000VND Vs. 700,000VND from HUI. I just picked a random date. Granted Vietnam Airlines is the reverse, cheaper from HUI than from DAD. I was just suggesting what might be a cheaper way to fly, because JetStar has been really cheap out of DAD in the past.