A shame this thread is so old. I'd be curious to hear if there are big differences in durability between say, nailhead, sharkskin, birdseye, herringbone, etc.
I don't believe S-number and fabric weight are the only factors that contribute to a cloth's durability. Tightness of the weave and type of weave may also be factors.
Is there anyone who knows more about this and is willing to share?