In general, a good airline. However a few points of inconsistency that need to be addressed:
1) Check-in: We could not get upgraded at check-in counter in Noi Bai airport (VN) because we were told "the reservation system is not equipped to do so at the counter"! This was surprising because the same airline was able to offer this service to us at the check-in counter at Da Nang airport (also in VN) a week earlier!!! Why the inconsistency?
In any case, the flight was half empty so we were able to sit where we wanted and saved our money!!
2) Security measures: We had been flying internally with VN airlines during our trip from one city to another and never had any hassles with our electronic devices (laptop, tablets, cameras) which we always placed in our checked luggage. Helas, it was not true at Noi Bai! They marched me back into the X-ray area once we had cleared security so that I had to rummage through my checked suitcases and took all these devices out and carry them as hand luggage. The explanation was that "it was not safe to leave them inside the suitcases in the hold". The airline staff in all our other internal flights never requested us to do that! I then had to queue again for another 15 minutes to clear security even though these devices had already been cleared at the X-ray chamber just now! Suffice to say I was very happy and grateful for the experience, all the more at a capital city airport!
3) In-flight service: Stewardesses looked like they had a bad day. Wish they had smiled a little more.
Taking into account the other internal flights with VN airlines during our trip, I think this was just a glitch. However, what was that saying "One scabby sheep is enough to spoil the whole flock”?