My mate, an ex-Aussie army vet went back about 20 years ago and he said some were pretty unfriendly towards him ,obviously pegged him as a Vietnam Vet.Had trouble with the customs when he was leaving, with them going through ALL his stuff.He went back again about 9 years ago and he said the whole place and attitude had changed completely. Friendly people etc.He had a great time.
I found the same in a small way.I first went over to Laos about 15years ago.I have been a few times since.The customs/immigration folk were surly and unfriendly as were some of the population.The last time I went about a year back, The boss at the customs came and helped me personally and the Lao themselves were a lot more friendly.