I'm confused too, I could swear all of the "quilting machines" I've seen or stitched with are rotary. APQS, JUKI TL98, and even the Tin Lizzy is, I think. I only have one of those here ATM but I will go verify later. The first 2 make beautiful straight stitches, the 3rd needs more set up before I can judge it fairly but I don't recall a noticeable twist. One reason I don't love the oscillating is that it seems noisier than a rotary. That said, I was also completely unable to bond with my 115 which is a rotary and love my 15. I just know it's loud comparatively.