I took a Bernina class once where the teacher said that Organ needles are fine for straight stitching but they are just a tiny bit longer than other needles and so were not good for Embroidery (and decorative ?) stitches. Apparently, during those ,the needles moves from side to side and can hit the bobbin case as it rotates. Not sure if I explained it correctly or if it is true but since I stock up when they are on sale, I just use Schmetz titanium needles.