I have several pairs of these for my heels. I find that they give some cushioning, though nothing outstanding. My feet still hurt at the end of the night, though not as bad as they would without them.
They are quite expensive for what they are (a cushy piece of plastic), but they do alleviate some of the pain associated when wearing high heels. I never wear heels (we are technically not allowed to in my line of work), so for special occasions these are a must have for me. Without them my feet start hurting almost immediately.
I would buy them again, and would not wear a pair of high heels without them.
I liked the fact that these wee cushions can not be seen easily when wearing open shoes. They really did make my feet hurt less in heels. However...I did need to make sure they were secured properly and when wearing boots I found sliding my foot into the boot would often move the cushion slightly out of place.
Tips: Make sure they are secure before walking in your shoes.