One of the things that makes the Apollo full foot fins so good is the compound of natural rubber they use, or at least used on the pairs that I have. They will not irritate or blister the back of your heel. The rubber is incredibly silky. The various plastic materials used in most fins can be brutal on your feet. The Appllos are softer and smoother inside than any dive sock. It's not an exaggeration to describe the feel of them on your feet as pleasurable. A good full foot fin is also more efficient; that's why free divers use them. I agree that the reality walking across rough terrain limits their usefulness.