I have one that I got thinking it would make basting my quilt tops easier, but found I didn't like it. I'd rather just FMQ the old-fashioned way since I can quilt larger designs without it. My machines have 7" throats and the frame takes up some of the throat space. I think I ended up being only able to quilt a 3 or 4 inch strip across the quilt each time before having to re-roll it.
Rob