Wonder Under is not stiff, it is not gummy on the needles when you sew, and it has never peeled like Heat n Bond or Steam a Seam on me. I found heat n bond would gum up my needles.
Wonder Under is bondable on both sides. I've drawn letters for applique, everything and sundrey. I enjoy using it and don't find it to be so stiff on anything I've used it on.
Enjoy!