I love these socks!  I've attempted to find comfortable "no show" socks for a few years.  Most either slip off my heel, or have elastic that is so tight it digs into my heel.  After wearing them for an hour or two, I have a painful groove on the back of my heel, and typically need to switch to to other socks and shoes.  Much to my delight, these socks are extremely comfortable.  I can wear them for a full day without any pain or discomfort.