First of all, I think this "UNPAVED" surface is the best gravel simulation in AC (what I tried). I'm sorry I don't know how you got that. The gravel.wav sound is more than enough to feel like a real gravel stage.
I give 3 stars, because the snow sound is too loud i think. It is very disturbing on my pro system. Please tell me how can I make this sound softer, then it will be the perfect solution for different surface training.
Thank you very much for your work!