I haven't been there in a few years but I can add my 2 cents anyways.
What are you riding, ATV's, Bikes, or 4WD (truck/jeep type thing)?
We were able to cover the entire park in about a half a days riding on our ATV's. I just found it to be too small (keep in mind things may have changed since I was there). There were some impressive things. There are some very scary single tracks up some incredibly steep climbs. There is a very challenging 4-wheeler hill climb area, it was even pretty damn scary on my ATV and I could have bailed if need be.
There is a rock crawler area for trucks, and an easy class mx style practice course (great for kids or beginners). There are some nice views and some fun hills to climb. On the down side is the red dirt, it will leach it's way out of your machine everytime it gets wet in the future, and your clothing will never be the same.
Have fun, update us on your thoughts after you give it a try.