I haven't used a Golite bag, but I really like my Cabelas Boundary Waters 40'F goose down mummy bag.  Mine is about 7-8 years old and came with a real nice drybag.  I use it all the time.  It is just the right weight for summer use in BW/Quetico unless you have a really hot July night.  I also have a 20'F one as well which I use for fall trips.  For winter camping I put either the 40' or the 20', depending on how cold it will get (10' above versus 10' below) inside a synthetic bag and have a really nice cold weather sleep system.
Down bags are great as long as you keep them dry.  On a rainy fall or spring trip you have to be really diligent to keep the insid of your tent dry with proper venting and waterproofing.  The high humidity can start to cause a down bag to loose loft.  I put it inside the dry bag whenever I'm not sleeping in it, and air it often when conditions are like that.  Winter and summer don't seem to be a problem.