Here is something to think about. If you have a tent that doesn't leak..... down is your friend. My tent doesn't leak. If I was backpacking into the back country I will use down or synth depending on the time of year and weather. If for some reason your down bag did get wet while on tour it's not like your 15 miles back up a trail. Your a town away from a dryer. Unless your doing remote touring it doesn't matter. Use what you have. I'm more concerned with bulk on tour and weight for the rating of the bag. On this front the down bag is the winner. My 20 degree bag weighs less than 2 pounds and packs down very small.

As far as cold feet.... leave your socks on. Keep your shoes in the bottom of the bag at night so they are toasty warm in the morning as well.

My 2 Cents.