Been to both Badlands and St. Joe's several times. Like them both.
Badlands is about 800 acres, little bit of everything riding-wise including trails, pea-gravel dune-like area, hill climbs, mud. Camping is so-so. It's one big open area with a shower house. They have electric/water hookups. Don't believe you're supposed to drink there, but that never stopped us, or slowed us down.
St. Joe's has a much larger riding area, about 2500 acres. It's an old lead mine and they used to have some nice water holes, but the EPA got involved, and they rocked over nearly all of that. Finding mud is a challenge there. There are dunes and a lot of wooded trails. Some good hill climbing. Their camping facilities are stellar - some of the nicest you'll find. Drinking at the campsite is ok. They do have park rangers that frequent the place so if you're loud afterhours, they will come talk to you.
Most any kind of riding is good riding, IMO. Hope that helps.