I decided to test these pants out and they are way lighter than I expected. Knee bar approved durability and super stretchy. Outrageously comfy. Only negative is that the material makes a lot of swishing noise when walking.
As for the fit, I’m a slim dude: 5’9” 130 lbs 29” waist and the medium was a little too long/wide for my leg/waist. Returned and went for a small and it fits perfectly!