I used the long lines on Mazzy yesterday and she was perfect. I am such a ditz sometimes though....I put them on while she was on the crossties, and I was going to "drive" her over to the round pen, however, she had no idea what I was trying to do, so she tried lying down - down she went on her knees!!! I thought wow that would be a cool trick to teach her, but I didn't know what I was doing to make her do it. She tryed going down twice, until I finally decided to lead her over to the round pen instead of drive her. I only walked and trotted her, one becasue I didn't want to overwhelm her the first day using them, and second becasue it was too freaking hot. I also put open fron boots on her for the first time, and she was fine, didn't seem to mind or even notice they were on. She is suck a quick learner. So far, so good. I measured her again, and she is still 16.1.