These were very comfortable for a pilates workout. The feel of the fabric is so soft, and the bottom is very plushy, which I absolutely love. The socks start to feel tight throughout day at the foot opening, so I would not recommend wearing them outside of the time of your workout. However, I did not notice the cutout for your heel as I wore slides throughout the day with them on. I'm not sure the cutout is necessary, considering how well the grip is on the front of the sock, if that was intended. I think a full sock would have been fine, as well. The heel pull in the back flips down with some movement, but is unnoticeable feel-wise. There are also some raveling threads after their first wash that may be of concern in the future, in terms of upholding quality. These were very comfortable for a pilates workout. The feel of the fabric is so soft, and the bottom is very plushy, which I absolutely love. The socks start to feel tight throughout day at the foot opening, so I would not recommend wearing them outside of the time of your workout. However, I did not notice the cutout for your heel as I wore slides throughout the day with them on. I'm not sure the cutout is necessary, considering how well the grip is on the front of the sock, if that was intended. I think a full sock would have been fine, as well. The heel pull in the back flips down with some movement, but is unnoticeable feel-wise. There are also some raveling threads after their first wash that may be of concern in the future, in terms of upholding quality.