I apologize for the "tone," I understand that it come across as abrupt. I'm not a super hunter and have TONS of animals on the wall and am no means the gospel, however I have almost 20 years of testing equipment, designing and being asked to make suggestions, and no.... Im not a magazine writer that "thinks" he test gear. I have been a athlete for these companies and parent holders. I buy no means mean to come across as a jerk, and I apologize for thinking that everyone is 6'. Equipment certainly is a preference....
Please don't confuse my advice with what I prefer....
Down certainly is more compactable and lighter you are correct. I LOVE DOWN!!!! I would rather be in down any day of the week. It also becomes a worthless sack of feathers when it gets wet and doesn't dry out. Unfortunately weather models aren't always predictable.
GENARLY SPEAKING>>>> Unless each down feather is treated prior to stuffing, OR THE Outershell of the bag is a Water proofing system of some sort such as Gore-Tex or another synthetic membrane, wet feathers will loose there loft. Once this occurs, the bag needs to be aired out and dried. There are companies out there that have rectified this situation...... for instance... MT Hardwear has started actually treating the down prior to being blown/sewn into place. They use a product they call Q shield elite.
Here is a link for there water proof down....
http://www.mountainhardwear.com/innovation.htmlFeathered friends makes Excellent gear, they are especially nice if you need a custom bag made and are much more reasonable than you would think. Keep this in mind for true wilderness hunting as well, if your a "bigger" or "taller" person try looking at Feathered friends. They make excellent custom bags for a reasonable price. Good sleep in the BC will help with the mental game of multi day trips.
If I were to own one bag it would be down, with a bivy.... But I don't....I own several.
Keep this in mind... When you see all these climbers and back county skiers using down bags (I'm guilty as charged) .....the snow/ice is a relatively dry environment. The idea that snow is a dry environment is counter intuitive I understand. As well as hunting out of maritime mountain ranges is a whole different story. If I lived some where east of Ellensburg.... I wouldn't own anything buy down. Unfortunately I live, hunt and test gear mountains that are subject to Maritime snowpack and weather patterns, so I own synthetics also.
Lets get back to you get what you pay for...... I would rather have a nice synthetic bag over a bottom of the line down bag. Remember this is the in of climbing and summer mountaineering season...... If your going to buy an nice bag.... now is the time.
Properly stored while not in use, down bags can last a lifetime.
Good luck and I once again apologize for my "tone." Its difficult for me type my town of voice, this is why I don't text with my wife anymore.
Sincerly and respectfully