I have a manual version. It looks very nice. However, the curvature of the two pulleys is frozen in the belt, creating two humps. These humps make the slider twitch and are particularly noticeable without a flywheel. I've attached a video clip to show this. When I contacted their support they offered to send a new belt but the belt never arrived. With the flywheel attached, the movement is smoother, but I still feel jerky when I push it. If it wasn't for the belt issue I would give 5 stars. After a few tries, I came to the conclusion that even if the device is perfectly smooth, I can't move it at a constant speed, and I also want the camera to track the movement. object while moving the slider. So manual slider is not for me. hp At second glance, stuttering is probably not caused by the reason mentioned above. It appears that the pulleys/gears are not perfectly round.