If you are planning on using your sleeping bag in Washington and Alaska down is a good choice unless you just can't keep it dry. I have used both in western Washington for trips up to three weeks and in coastal Alaska for trips lasting several months. All trips were three-season, not deep winter. With this experience under my belt I can say that I prefer down to any synthetic I have ever used. I can also say that, while wet synthetic may be warmer than wet down, the difference is pretty small. If I got either material wet, I would sooner build a fire and sleep, or not, near it's warmth. Synthetic looses its loft much quicker than does down; here I'm talking months versus years. And, a synthetic bag weighs nearly twice what down does for equivalent warmth. Of course, it is your money and your decision but you certainly should listen to the experienced people on this forum before you make a final choice.