We have the chance to have Mr.Boun, as tour guide for two days in Angkor. I can say that he is one of best tour guides, we had. And yes, we travel a lot. He knows the history and facts by heart.  Very positive and cheerful person. Knows the best spots to take a picture, knows from where to start in order to have the opportunity to see everything.  Realy great experience because of him. If you are in the Siam Reap area and searching for a tour guide, you could contact Mr.Boun, quite shure that ata the end you will be reallly satisfied.  Best regards from Bulgaria.