I've been to slade once. I'm not able to join you guys on the 23rd, but thought I'd offer a little input from my experience there.
It's a great place to wheel, nice scenery and lots of great obstacles. It's probably 2nd best in the region, with Harlan County, KY being #1.
However, it's a huge area, and it's also pretty easy to end up on private property. You can get yourself into trouble if you end up somewhere that you are not supposed to be. And with it being such a large area, it'd be easy to get completely lost. You might not see that as a problem if you are really adventurous - but if one of you guys get hurt and need help, then it's a major problem if you can't find your way out quickly. Also, some of the obstacles are pretty "hard-core" - meaning that the consequence of picking the wrong line could result in a 100'+ fall off of a ledge/cliff.
This is just my 2-cents. If you are interested in my recommendation - I'd suggest tagging along with a club-organized trail ride to Slade, where you'd have an opportunity to follow people that know where they are going.
If it's just you and your friend for the 23rd, you might want to check out Big Rock Off Road Park, especially if you haven't been there recently. They've continued to add new trails. They just recently opened their "Jeep trail", which is not "hard core" by any means, but you can still have some fun on it. It's pretty well marked. And it's closer than Slade.