I had read a lot about the ‘American war’ and wanted to visit this area. I even managed to convince my wife to come on this tour, and we both loved it, despite her attending mostly for my benefit! Vu really brings the area to life with documentary pictures on his iPad and detailed explanations of all the areas and the history around them. He has a huge knowledge of the area in general, not just from the recent war but back into French colonial times. 
Seeing places like Khe Sanh and the Rockpile which were household names during the war is so significant when visiting Vietnam. We were lucky enough to meet a NVA veteran visiting the national cemetery and he spoke to us for a long time (Mr Vu translating) about his time deployed near Danang and the DMZ doing reconnaissance. Many visitors don’t go to this area (despite it being really quite scenic) which I think is to the detriment of any trip. Visiting these places and considering how overseas intervention shaped and changed this country can really frame the rest of your trip. If you have a spare 24 hrs to stay in Dong Ha and do this tour I would thoroughly recommend it. (As a side note, 24hrs in Dong Ha is plenty for any traveller I think!)
A guide like Mr. Vu is essential because finding these areas today would be too hard alone. He was very accommodating and was able to drop us back off at the station at the end of the tour for our journey up to the National Park. Thanks Vu!