These are great! I had trouble with raw/sore/blistering nipples when I started nursing and have used nipple-shells to help protect then, but these are wonderful for between times... They don't don't get stuck!!! And I can easily wash them in my bra-bag and reuse them!
These are great. Even after a days use I still feel like that are fresh. However, I wear them only once between washing. I did experience leakage with my let down but that's expected with cotton.