I have used them, and to be honest, they're more trouble than they're worth. They tend to get caught on each other. If I'm not using a great deal of a particular color, I let the strand hang. It's much, much easier to pull on strand up through the inevitable tangle than to try to untangle bobbins or balls. If I'm using a lot of a particular color, then I might roll a small ball.
I was just going to say that Kaffe Fassett, the king of color, recommends letting his strands hang, and then looked at your link. :lol: