Muine is a small village around 3 hours north from Ho Chi Ming City if going by car, we went there by car and that was a good choice as there are so many scenic points along the route.
We checked in to the hotel which was located near the beach and got a fantastic view over all the beach. The sand there is good and the water is not rough, but there is wind enough to do kite surfing. Which is available everywhere and seem like the main activity there.
In the evening we went along the beach and found some very local seafood restaurants at the end of the beach to the north, there they had around 20 restaurants with various seafood in many qualities. Make sure you see it swim before you eat it, as it otherwise might be from yesterday. The sand dunes is worth a visit in Muine, there you can surf on the sand and get some fabulous pictures and it is a very fun activity for the whole family.
Muine is more private than Nha Trang and I would actually prefer Muine if we had to choose.