As Vagabond has rightly explained some of the issues.
We came from Brisbane but had been staying in VN for 1/3 months a year for a long time. Our advice would be to stay in Saigon for a period of time, travel around and see whether you could live here. VN is our home, we love it but it's not for everybody, major adjustments have to be made to your thinking and lifestyle.
We have noticed that for reasons which we don't understand or care, expats that we have come across, in person, are not friendly but we have made many Vietnamese friends, probably because my wife is Vietnamese and speaks the language although she was brought up in Australia.
We also notice that Vn is awash with Teachers.
Have a holiday here and see what you think and feel...
Mike