Samuel, you don't wash your down?
Wow, I have always treated down like regular clothing. Even if I always wear long johns & socks in a bag, oils still build up. 'Corse, mild soap, not detergent and ususally 1/4-1/2 the ammount the manufacturer recommends.
My Super Stretch UL down hugger is still going nearly new after 6-7 years. Even my 40F degree bag, about 11 years old or so, is in excelent condition after about 40 or so washings, though the hood has some stains and there is one patch on it. I typically head out for about 30 nights per year before I retired. The past three years has been closer to 60 or more nights.
Don't send them to the land fill. Send them to me!!!
Seriously, the only problem I have with down is when it gets dirty or wet. Wet is avoidable. Dirt/oil can be laundered out. Down has been known to last longer than 30 years with fairly intermitant use, such as 30-40 nights a year. It's just dam expensive to buy, initially. It should last at least 15 years of fairly constant use, say 180 nights per year. They used to be quite painfull to wash, often about a half a day or more at the laundromat (rinsing, washing, rinsing, rinsing.) Nowdays, with no agitators in my home machine, it goes pretty easy.