If I have been lazy and not pre wound before beginning a project or just need a little of a different color I use the winder because I hate to remove project from under needle, unthread, set up for bobbin wind, then pop into top load and re thread and then go! Except if I use my old Viking #1+, I can wind without all that..it has bottom load bobbin.....the other two have top load bobbins! not really fond of that feature but whatever