My wife and I rode there a few weeks ago. The park is very nice. It's definitely not Hatfield Mccoy or Windrock, but there are over 100 miles of trails. There's several places with a black diamond rating. There was no mud when we were there and it was very dusty, but definitely worth doing, especially if you have free passes
Rode there last weekend It's only about 30 minutes from my house so very easy to just load up and go for a few hour get away anytime. Have a family yearly season pass too. Last weekend was very very dusty on Saturday morning but around 4 pm it started raining hard for 3 hours. Woohoo.. was a lot of fun then. Was with a group and I hate riding in a group when it's dusty but even when it's dry you can find mud. The only time I got stuck was before it started raining.. haha
The first trail you'll probably take is Trail 6. It's a green trail and goes all over and pretty long. Trail 4 is a blue but I don't find it any harder than trail 6 actually. Trail 5 isn't bad but has some good mud off of it. Now the Swamp isn't marked on the map but there's trails all through it that are not groomed and it's tough.
Trail 19 is pretty rough too probably want to stay clear of that one for awhile.
Overall it's been a great place to ride. Plenty of service roads and marked trails. Can't really get lost. There's all types of terrain there. If you wanted, you could just stay on green trails all day and cruise around. Also, there's almost always someone around especially on the weekends. It can get pretty busy but it's very spread out.