I have both. I got them through Nancy's Notions. I once worked for a Bernina Dealer who also did alterations and custom dressmaking. We often used the bobbin one on our serger when we were doing an alteration or small job. It allowed us to use regular thread rather than having to open a large serger spool that we may not have any more use for in the future. While there is a lot of serger thread out there the colors are not as plentiful. The only problem with serger thread in the sewing machine is the additional lint. Make sure you clean your machine often when using serger thread for regular sewing or quilting.