A friend of mine who has most every toy got the Sidewinder - and quickly passed it on. She now uses pre-wound.
Personally, I don't understand the need for a separate item to wind bobbins? I bought a couple of tubes of the empty Bernina bobbins and wind several at a time, then am good to go for good long time. I use Aurifil, which is a finer thread than some, so am getting a lot on the bobbin. (If you are following Bonnie Hunter's current mystery, I've done steps one and two without changing the bobbin.)