I am running a 1/2 marathon that will be about 12.00 miles on crusher dust. There will be two section of pavement about 400 meters long, and one section of gravelly dirt road about 800m max.
I've got the oppation between racing shoes (brooks T7), nike waffle racers spikeless, or Brooks mach 14 w/spikes.
I run some intervals on a crusher dust trail in the Mach14s and they work well. However I'm not sure how the paved sections will play out, or even the gravel/dirt road.