I have spent abit of time there. Great place! Lots of great CW material. I hate the way you have to search for maps that you want to view, but the rest of the place is great. Go to spend the day and don't take anyone with you as they will only hinder your research. I made the mistake of taking my wife with me first time I went. After about an hour she was ready to go, while I still wanted to search the rest of the day. At first the researching is slow since you are just learning. It speeds up the more you learn the place and how to research there.
If you like Civil War history..... or any other history of Arkansas you owe it to yourself to make the trip.