Quick Review. Good: They spark so much you can hear it. Bad: If you put too much weight on them they really grab. However, if you've got a light touch they're ok. Odd: Due to the crescent shape, if the sliders are on a certain way[1] then the wind pushes on them, which pushes your legs out a bit at speed. An odd feeling. [1] Slider is in a C shape. Direction of travel to the right: C ->