well, i'm quite the newbie.
but i have mine set newest to oldest. but i frequently scroll through the main threads to see what other posts have been out there.
also, if i read one post, i'll scroll to the bottom and look at the list of other posts that have similar subjects to it. i've found things from 2, 3yrs ago. it's nice to be able to go back that far and read things that i've missed.