Hey, sorry I was a little vague in the description. It is made of a Cuben/50d Poly hybrid fabric. The bottom of the pack is double-reinforced 150d. Also, this pack is waterproof, whereas dyneema (PU Coating) is not.
The HMG pack has more volume (65 liters counting the external pockets):
Interior Storage Volume: 3400 cubic inch main compartment.
Exterior Storage Volume: 600 cubic inch mesh outer pockets (300 cu in main pocket; 150 cu in side pockets).
The recommended load of the swift is 12-30lbs whereas the windrider's is 20-40lbs.
This pack is marketed more towards ultralight mountaineering than backpacking.
The material is bomber - sort of like a McHale pack. Dyneema is fairly resistant to abrasion, but nowhere near the same level of HMG's hybrid cuben.
Also some differences in this pack that factor in weight:
-Removable internal aluminum stays
-Wing style belt
-Waterproof belt pockets
Six moon designs has these as well and add up to nearly 9 ounces:
-Wing Belt (medium): 4.1 oz
-Aluminum Hoop Stay: 4.6 oz
Factor these in and your swift is near 25 ounces, and hold 10 liters less if I'm not mistaken.