Hi, My daughter-in-law gave me a Side Winder for Christmas a couple of years ago. I have not used the bobbin winder on my sewing machine since.
It is so nice not having to unthread my machine to wind a bobbin and then put everything back together again. The only problem when you change color of threads to have two of the same color. It defeats your purpose of having a Side Winder if you have to take the spool off of you machine to wind the bobbin, IMHO
Henriellen