You need to have a foot on it or all you'll do is fight with flagging and skipped stitches. Actually, if you can loosen the presser foot pressure enough to move the quilt around under the foot, you can use the regular straight stitch foot. I have a 15 clone that I do most of my free motion work with and that's how I use her. Orphan Annie doesn't like any other feet I've tried on her, and sometimes I even forget to lower the feed dogs, it makes no difference. You just have to know your machine, what it will and won't do for you, and that just takes practicing a lot.
Cari