The synthetic bags are definitely better in conditions where the bag may get wet. For years, I carried a synthetic for just that reason. Then they came out with internal frame packs, into which my bulky synthetic bag just won't fit. I bought a down bag.

It's pretty darn cool when you can compress your bag down to the size of a loaf of bread. Also, my down bag weighs less than half of my old synthetic bag.

Of course, you do have to be really really careful not to get a down bag wet. I keep it in the dry sack until I've got my tent fully up, and then I unroll the bag inside the tent. I've got a Big Agnes Sunnyslope 2 tent. I've gone through serious thunderstorms with nary a drop getting inside.

But as Greg pointed out, I'm a hiker not a touring cyclist. You know what they say, "take what you liked and leave the rest."

Happy trails (happy tours?)...