I like the Ferderdecken set, because it is very well made. Both blankets are supplied attached. After unpacking I could find no unpleasant chemical odors. If yes can be good because the duvet "Made in China" are. One of the blankets I washed the same test at 60 degrees in the washing machine. Within a day, the ceiling was then dried completely. I think a big part of that has these chambers technique at the ceiling. Thus, the springs do not clump together so much.
From sleeping ago I find the ceiling especially good because they are not so hard after all. I personally do not like it so if you will be crushed in the bed of the blanket due to the weight.