This was one of the things I knew I really wanted to see when I was in Cambodia and I was not disappointed. In advance i hired a guide (Kheng Yon) and car/driver and did a 2 day trip (stopped to see Beng Mealea and Koh Ker temples along the way as well as eating in villages and staying overnight in a town near Preah Vihear Temple). We went to Preah Vihear first thing in the morning and we took the first truck up the mountain, so I was the only tourist there! (another truck was coming up when I was leaving).

The road up is very nicely paved, but is extremely steep!!! The 4-wheel drive trucks up have seats in the back where you ride and hang on! The have a big bin of cigarettes so you can buy a carton to toss to the soldiers along the road. I am not big on cigarettes, but it seems this is kind of expected, so that's fine.

When we arrived at Preah Vihear Temple, my guide, Yon, let me know that he would not be allowed to talk to me while we were there, but he would fill me in at the end of the tour. The people at Preah Vihear assigned me a local guide instead, but they did not have any English speaking guides! Yon let me know later that they do this to keep the money local and because they believe that local people know and understand the local history better. I did tip my local guide at the end even though i could not understand a word he said. None of this detracted from my experience though (if anything it was just kind of comical and let me really explore the temple on my own, which i prefer anyway). My guess is that with the huge increase in tourism there, eventually they will work out how to better serve foreign tourists, but I kind of like it the way it is right now anyway.

The big differences between this temple and others is
1. the layout & location--it was built by multiple kings over centuries and stretches along the mountain top. The views are just beautiful. There is just something about a temple on a mountaintop that you can't beat. I forget what the Cambodians were always saying...something about it being the real home for the gods or something like that.
2. the Military presence and history of conflict. There are soldiers and their families everywhere all over this temple. I wish i had brought more small bills ($1) with me for tips, as i ran out pretty quickly and it is pretty expected to tip. I didn't realize that a big part of the reason for this is that they make very little salary from the government and life can be pretty difficult there. There are also people selling treats that you can buy to give them. Some of the soldiers spoke some English and were friendly and asked where I was from. Overall, it gives the place a bit of a weird vibe, but I liked it and I never felt unsafe there.

A couple of tips:
Guide: I have read on here that it is completely necessary to have a guide for this trip. I disagree, I think you could hire just a car/driver, especially if they spoke English (if they didn't, you will have some communication problems along the way, but if you are adventurous, i think you could do it), BUT I really loved my guide and definitely think my experience was more full having him there. It was the only time on my trip that i hired a guide and so he answered a lot of my questions about Cambodia in general and about other temples and whatnot too. Yon was friendly and extremely smart and his English was PERFECT and because we both are teachers, we had some great conversations about education in our two countries. I let him know i wanted to try all kinds of foods that I could, so when we were at restaurants (usually where no one spoke english), he would order me interesting things to try, which was great. I could probably have managed on my own, but it would have been a little difficult sometimes.

Hire a guide way in advance and keep checking back to make sure you are still booked. My first guide I reserved ended up double booking, but refered me to Yon, who was AWESOME and his price was really reasonable. If you want his contact info, feel free to private message me.

The Hindu carvings at the temple were wonderfully well-preserved, similar in detail to Bantrey Samre. The views from the top of the temple were also fantastic.

While the temple itself was great, I think I enjoyed the 3.5 hr car drive to the temple even more. It was great taking a quiet drive through the lush Cambodian countryside, especially after navigating the crush of tourists at Angkor Thom the day before. When you arrive at the base of the mountain, you have the option of taking a moto (for $5) or a pickup (for $25). I'd recommend taking the pickup as there are some parts of the mountain that are super steep (though quite thrilling!).

Based on the suggestion of another Tripadvisor reviewer, I booked the day trip from Siem Reap to Preah Vihear Temple through San Park at www.angkor-temple-guides.com. He did an excellent job explaining the mythology in the carvings and also has a wealth of knowledge about Cambodian culture.

Due to the remote location, the soldiers and families stationed here are very appreciative of any gifts. I'd suggest bringing some small gifts like granola bars or nice pens for the children.