I just came back from Cambodia, and use one day to visit this temple. (My hotel located in Siem Reap, I went to Preah Vihear as a day trip)
It will takes around 3.5hrs from Siem Reap to the ticket booth of Preah Vihear. Now the ticket is $5 per head. (but I find that a board read "$25 per a 6 ppl truck"). Your car need to stop at the ticket booth, then you will take a government car to carry on the travel. We no need to pass Thailand road as travel book suggested, instead, we travel on the new built road to the temple. The drive is really amazing, as the truck is open, we can taste the speed of the car, enjoy the view with no hindrance, as the road is quite steep, the feeling is comparable to a ride on roller coaster, except it is a real car. I think this journey is even more interesting than the temple itself.
The temple is in similar style to Angkor Wat, but the layout is different, it stretch from North to South. The cliff view close to the temple is really great, but the day we visit is very foggy, so our photos is not great.
We have lunch in the Soldiers' family camp, the food is not bad, besides, our tour guide Sophana cooked a dish for us~~
During the visit, the people there are quite curious about us, children will walk close to you and look at you.