I grew up running Coyote Canyon in San Diego County with my Dad, and back then it ranged from 2-7 on that scale, but we didn't have a rating system it was word of mouth "it's kind of hard in places"
Now I live in NC and I just compare everything to the Uwharrie rating systems.
For the OP
One thing I do recommend is, if all possible, meet the adjustor at the vehicle. They have the ability to add your aftermarket items to the total value. I was able to add to my beloved Accord and get more out of it..