I find that the gravel conditions can be dramatically different based on the weather. The first time I did it it was near record warm temps. The gravel was dusty & loose. Reminded me of Strada Bianche. The loose gravel caused a lot of grooves to be made with all the riders. Getting out of the grooves could be dicey.
If the weather has been cold & wet then It can be pretty messy. But it’s a great event all around.