BEWARE: Looks like the manufacturer is transitioning to acrylic. My review is for cotton. Acrylic will probably not be as nice. If you pick a different color, you may get a different fabric. The acrylic product should not be able to benefit from reviews citing the wonderful cotton fabric. I'm returning the acrylic pair I bought by mistake.
FOR THE COTTON PRODUCT ONLY:
These are the highest quality clothing items I've purchased in years. The fabric is soft and feels luxurious. Nice thickness--thick enough to be warm, but it doesn't feel like you're buried alive in fabric. Often you pay more for quality, but just get pricey junk, but these are worth the price. I'm going to be living in these all winter. Great for working out, too. Sure the tech fabrics wick well, but cotton just feels better.
These might be tad thick if you're wearing them under tight pants, but I think it's worth it because thin polyester thermals are gross and not that warm.
I bought two sets of these: small and medium. I'm a man-shaped woman with a 30-inch waist (130 lbs). The small is just slightly tight in the waist and the legs are a little snug, but still wearable. The medium fits well. Length is good for my 32-inch inseam.