I've been there three times now, in my nearly stock TJ jeep and it ROCKS (no pun intended).
I've got a video or two here--> YouTube - GeneralTJWillys's Channel
What's it REALLY like? It's really like a LOT of fun for anything you have. ATV, Jeep, Pickup, Dirtbike/Enduro, and even the new crop of larger 4 place ATV's. There is everything from mild to wild there and the scenery at the tops of the mountains is breathtaking!! Go in the fall for the best pics!!
Speaking of pics.
Picasa Web Albums - Tracy - Harlan Fall C...
I'm going to try to get some more video posted later. I'll add the link when it's ready.
PS...my avatar pic was taken there.