I don't know how they are now, but I can comment on last year. It's about a 2 mile long section. In that section it varies from hard dirt with some rocks, and potholes, to hard packed sand, to soft, loose sand.
The most difficult part is where its soft sand. I rode 23c tires, last year, and If I did it again I'd do 25c for a little more stability in the sand.
On the first lap doing the nuetralized rollout, it fell very unstable sliding in the sand. However, after that at race speed, the momentum helped a lot. You just have to be prepared for the bike to fishtail around a bit and catch it when the tires wash out.
Pedaling low cadence/ big gear seems to help in the sand.
also its a bit dicey to move up on the sandy sections, so it pays to get up front before the first turn onto the dirt.
On the whole, I had a blast last year, and would definitely reccomend doing it.