I'm going to have to agree with Keith. I've owned several high quality synthetic bags and none lasted more than a year (I did use them alot - roughly every other weekend and more). They were from reputable manufacturers (Sierra Designs and North Face - from when NF was good) and I was able to return them when they lost their loft. I eventually talked them into a swap for down bags. That was 15 years ago and I still own those down bags and they still function wonderfully. I have since switched to a WM Ultralight to save weight.

If you don't use them too much and you store them properly - I'm sure that you'll get your moneys worth out of the synthetic bag, but over the long haul I think down wins the race.

rionada