Our flights were with Vietnam Airlines. We had to transit via Hanoi and HCMC. Our luggage came through quickly at Hanoi, we cleared immigration quickly as an official was managing the queue system and - maybe we were just lucky - she diverted us to a new lane that was just opening.
We were then greeted by specialist Vietnam Airlines transit staff who dealt with the transfer of our bags from the international terminal to the domestic terminal for our next flight to SGN.
We didn't have to handle our bags after that until we collected them off the conveyor at Melbourne after our third flight from HCMC! At Hanoi we were directed to the terminal transit bus and all check-in activity for flights was handled quickly. The domestic terminal at Hanoi was busy but had plenty of choice in terms of shopping and outlets.
However the international terminal at SGN/HCMC was the only basic in comparison, with a poor selection of shops and food outlets. Before departure from the U.K. we had been in regular contact with the Vietnam Airlines reservation team who had always answered our questions promptly.
We had hoped that the visa-free transit tours might have been reinstated since their cancelation owing to Covid, but sadly this has not yet happened.
7+ hours in SGN airport could have been avoided though, like one of our fellow travelers who had booked herself a nearby budget hotel room for the layover. On that day there was a torrential thunderstorm and rain so we probably wouldn't have enjoyed the city tour as much as we would have hoped - had it been available!
Please Vietnam, reinstate this tour! Our flights back to the U.K. will only involve one shorter layover in Hanoi within the international terminal. We'll let you know how that goes.
However our experience of Vietnam and its airline as fleeting transit passengers had been excellent so far, so let's see a little more optimism. We'd return, and we'd spend more time in Vietnam next time we're traveling from the U.K. to Australia or Fiji.