There is nothing like a comforter (duvet? never heard that word b4). A quilt I think is the original comforter and I have both to keep warm in winter. Haven't used a blanket in years.
So we can avoid a VS. vs VS. argument I'll throw this history lesson in. In WWII, Adolf approved a "test" of how to warm-up downed pilots from freezing waters as fast as possible. After many months of testing the team concluded that a downed pilot regained consciousness and 98.6 the fastest,
when he was put in a bed with a naked female.