Another great advantage is, if properly cared for, down sleeping bags are very durable and will last about twice the amount of time as a synthetic one.  This is important to keep in mind when making a final decision on which sleeping bag to buy.

One disadvantage to a down sleeping bag is that is requires more maintenance and care.  It will either need to be hand washed or put into a front load washer at a laundromat.  Either way they must be handled with care as to not ruin the down.

Another disadvantage to down is if it gets wet it take a lot longer to dry.  So if you are going to be in wet conditions a synthetic fiber fill sleeping bag may be a better choice.  Or you can add a water resistant shell to your down fill sleeping bag.

One final disadvantage to down sleeping bags is that they are more expensive than synthetic ones.  So if you are on a tight budget, you may want to consider a synthetic one.  However, keep in mind that a down sleeping bag, if properly cared for, will last longer and provides a lot of warmth and comfort, as well as being very light weight.  So when it comes to choosing a sleeping bag, go for overall quality if you can afford it.

Down sleep bags use real down feathers for their fill.  There are three main types: hi-loft down, duck down and goose down.  Hi-loft down is made out of finer goose down and provides the most warmth.  For expeditions in cold weather high-loft is recommended.  Goose down is a higher quality than duck down and is therefore a bit more expensive, but for regular camping they are both good choices.