I finally bought the one that is used with an iron last year and I really like it.
Getting the binding on is easier for me when it's pressed, and when you're making binding for queen and king sized quilts, it's a lot of binding. With this, once my binding is sewn to the length I need, I run it through and it's neatly pressed in half in just a couple of minutes with no burnt fingertips. I cut my binding 2-1/8", fold the end to get it started, set the iron on, and pull it through with a perfectly centered fold.
I do like the one that Terry Rowland makes, and if I'd seen that before buying this, I would have made one. The really nice thing about hers is that if you want to change the width of your binding, you can easily adjust the guide that the needles make.