The pillows that came with my new couches (2 of them) were stiff and not comfortable.  They would not conform to one's body.  So I ordered these fillers; removed the original stuffing from all of the pillows; and inserted these innerlined pillow fillers.  That was two years ago.  I am completely pleased with the outcome and they are holding up just fine.  They are easy to "fluff" up and that keeps them comfortable to use.

Pros: Easy to fluff; stay comfortable; make my pillows look great.
Cons: None