When it’s dry, goose down is definitely an efficient insulating material.  When it gets wet, however, it tends to lose that ability.  The synthetic materials - hollofil, quallofil, and others - are similar products by different manufacturers and are reliable insulators, whether wet or dry.  Pound for pound, I believe down has more insulating capabilities overall, but keep in mind where you are going and how wet it will be there.

A sleeping bag with 3 lbs of synthetic insulation is good for 25°-35° temperatures.   For 0°,  you’ll want an expedition bag with 4-5 lbs of insulation, a cotton or synthetic insert (kind of like an inner sleeve), and a waterproof shell for rain and/or condensation protection.  Most important, get a good quality insulated sleeping pad that goes the whole length of your body, not the torso size.  Be sure to also wear socks, pajamas, and a knit cap to bed.  If you get warm, unzip the bag a little.

1) Try turning on an electric fan. They’re cheap and can be found at most major retailers (Wal Mart, target). If the fan vibrates or rattles on the floor or table, just put a towel under it. On colder nights, try facing the fan away from you so you won’t get too chilly. On warmer nights, it adds a nice breeze to keep you cool. In addition to maintaing climate control, the “humming” of the fan can help induce sleep.

2) Some campers have benefitted from sound machines or soothing cd’s The peaceful sound of birds in a rainforest or crashing ocean waves might do just the trick for blocking out the noise outside your tent or trailer.