I've been thinking about trying this for some time, and it finally worked into my 50k training plan as a race simulation. I run this ridge often so it is great to finally do the full out and back! Starting out, I saw a bear cub (yearling?) in the first half mile of the class IV road section. Both of us were appropriately spooked!
I brought 2L of water with electrolyte and another 500mL of plain water and that was just enough (ran out at the high point before descent). I ate a homemade chocolate chip cookie, Larabar, a handful of grapes and another of gummy bears. I used poles for the ascents, but put them away the rest of the time. I saw 5 hikers on the AT (most of them 2x) and nobody else on the Orange Diamond Ridge Trail.
Editor: The time elapsed was estimated to and from the junction at US route 4 (Dartmouth College Highway) from the Strava file, which was for a longer run.