With Berghaus, we've created the 550g Hyper 37L rucksack, by cutting down on pockets and everything superfluous. It has extra-wide shoulder straps and a belt. I only use the chest strap while running downhill as the extra speed makes it move more. When it's full, it's firm on my back and with only 10kg I don't need to adjust with the strap tensions during the day.
I don't believe in un-cushioned soles. I've used Nike Air Pegasus for over 20 years. I prefer the road running version, even for trails because of their lightness and flexibility especially on textured technical surfaces. But they don't last, so I'm using the Nike Air Pegasus Trail for this trip, and expect to get through three pairs.
I helped Berghaus's engineers test the Vapourlight HyperTherm long sleeve top. They attached temperature probes to monitor where I generate and lose heat while running, and were able to tailor the insulation. It's reversible HydroLoft. In cold weather I wear the air-trapping surface on the inside, and when it's hot I reverse it making the insulation ineffective. I wore it to victory in the 174km Winter Spine Challenge.
The GHT500 sleeping bag is tailored specifically for the GHT, with a narrow fit, less down on the legs and back, and more on the top. Berghaus has removed all accessories, shortened the zip and reduced the weight down to 857g. It uses HydroDown which absorbs 75% less water than regular down and dries faster. That's critical as we don't have a tent or bivvy bag and we'll face subzero temperatures.