I have the F600 and I'm so in love with it. My head was turned with all those fancy stitches, alphabets and nearly endless stitch combinations. However, You are far more accomplished than I am, and the F600 may not fit as well with an experienced quilter. I am new-ish to quilting and like making gifts and home items and I really wanted all of the fancy stitches. I so enjoy playing with different combinations and I use lettering on all of my gifts and add the month and year on every quilt. I've made 3 twin quilts, a few throws and two more are coming down the pike. I'm not sure about a queen size quilt, but the twin quilts weren't that hard. And the F600 has performed all of it's tasks flawlessly. Well, except that the darn automatic threading feature is a bit hit and miss. Oh, well, nothing is perfect!