I wound my own, until I discovered Magna-glides. I too had a bobbin winder come with my longarm machine and while it did a good job it really can't compare to the Magna-glides. They seem to hold more thread and I just love the convenience of them. Tension has never really been an issue for me on my machine. If I did have bobbin tension issues it was usually because of user error (like lint in the bobbin case spring). But that said, I have never had backlash or a tension issue with magn-glide bobbins. Once I tried them I haven't looked back. I will pay for the convenience. I will still occasionally wind my own if I only need a small amount of a specific thread or color but 90% of what I do is magna-glide prewounds. BTW magna glides are marketed more to prevent backlash than tension issues. If you have an anti back lash spring in your bobbin case you have to remove it before using them. Again, never had a problem with backlash before using them either. For me it is pretty much all about convenience.