If you don't have a high clearance vehicle, this allows you to get from the end of a somewhat decent road at the end of FSR-92 to the Gardner Canyon trail.
If you want to do a loop hike up the Gardner Canyon trail and down the Cave Creek trail (or vice versa), this lets you accomplish that loop nicely.
Getting to the end of FSR-785 is a significantly rougher proposition than getting to the end of FSR-92. A friend of mine got there with his Subaru Forester, but I was frankly surprised.
Tom's hiking pages / tom@mmto.org