We had a fantastic trip - everything went exactly to plan.
The hotels were perfect and the transport and guides excellent. We especially liked Sam in central Vietnam. Traffic in Vietnam is crazy and we weren't really prepared for how long we could be stuck in rush hour traffic but that couldn't be helped.
As for suggestions - maybe fewer temples and less long drives. Some more local experiences would also be good. Like a cooking class or riding on motorbikes. My favourite parts of the holiday were just wandering around and seeing how the locals live in your country. Anyway, I'll definitely leave a review on Tripadvisor and recommend you to any friends travelling to Vietnam.
Thanks again for all of your help.