I found a nice post about the benefits
of using fleece liners with your cloth diapers over at
the Naturally Healthy Parenting blog.
I use fleece liners but not at every diaper change. Mostly when applying Grandma El's diaper rash cream on little man's buns as extra protection for the diaper. I have also started using them over night to help keep little man's skin extra dry when being in a diaper for 11 hours, especially if he is in a prefold and cover.
Do you use fleece liners?