Hey Kitetraveller123, how was your trip? I'm really interested in Vietnam. To visit there one day and get to kite too would be icing on the cake for me. If you have time, write us a trip report. I have looked at most of the Vietnam posts, but some of us really appreciate more detail and what you did besides kiting too.
I can really recommend Mui ne for kiting. You should go nov - mars to be sure to get wind. We were there in mid april and I catched the last week of wind so I was very lucky!! My first week it was blowing like crazy every day then suddenly after the 6-7 day someone pushed a button and the wind just disappeard!
We stayed in Pandanus resort (you can search for: "Pandanus Resort Phan Thiet, Mui Ne, Phan Thiet, Vietnam" on google maps) It's not at the main kitespot and tourist area. So you have the beach nearly for yourself! It's both positive and challenging: I had to do 2 self launches and I usually don't like that. But the wind is very smooth, the beach is wide so quite safe, except in the afternoon then the wind is too strong for self launch...
It's not a beginner spot, waves are building up quickly. I felt like a rooky in the beginning despite 10 years of kitesurfing. (I'm not used to waves, at home I only have sea waves not breaking waves)
Water is 27-28Celcius so you only need to protect against the sun that is nearly 90degrees above. There're some sandmosquitos that can bite you, especially if your blod is O- like me they'll like you a lot. After some days it starts to itch.
Off kitesurfing you can go:
1 - to a small desert with red sand
2 - to a little canyon
3 - walking on the main street... it's very long
4 - take some cableway to some hill
5 - check out a monastery
In the local area there's not so much to do so I would recommend to combine with some city sighseeing (we stayed a few days in Saigon) or hiking around in the near region.
Vietnam people are very friendly and helpfull!