The only issue we found was with Soda Lake being very wet and ridiculously slippery. As far as the 2wd vans, there were no spots we encountered that needed 4wd even though the luxury would likely have been used.
In my personal van, we were able to find the limits of the suspension capabilities pretty quick trying to keep up with the quicker rigs, but I doubt many would want to go that quick. I've got my eyes on a new setup to keep our average speed closer to 35mph in the rough stuff.
I would be very willing to do this trip again if people are interested.
2002 Ford E350 V10 Traveler
Vantage Optics Headlights