I agree, sew it on. Those iron-on patches don't stick worth a darn, in my opinion. My son is a boy scout and I don't even bother ironing them on anymore, because a) they're don't stick and b) he's rising through the ranks so fast I have to keep taking off the old patches and put on the new ones.
I just use a straight stitch just inside the satin stitch on the edge of the patch, in a color that matches. I bet you won't even notice it on the back of the quilt.