I got a sample of these and went out and bought more after using them. I kept them in the fridge and during those first few weeks of hot lumpy sorness they were truely invaluable.
I breast fed my first two children through huge amounts of pain and never really enjoyed the experience and I firmly believe this product along with a good nipple cream got me through those first few weeks almost pain free.
I found the discs lasted quite well over a few uses, so even after they had come out of the fridge, been worn and the taken out for a feed, I could pop them back in still get a "cooling" effect.
Also I liked that I could express a little milk onto my nipple, put the disc on and unlike a breast pad I didn't get dried out so the cracks healed very quickly I found.