Yes I have one. I bought it used on ebay a couple years ago. The prices have come way down now so it's much more affordable than what I paid.
The opening is OK. It turns alot of people off. But because of the throat size on my machine I wouldn't be able to use a larger one. I made a poster board "frame" to lay on top of my quilt as I use it to give me a visual of where I am from the edges of the sewing area.
It also helped me learn free motion without it. I never could do it before but for some reason,after using the fabric mover a while, I guess I got the hang of it. So now I free motion without the fabric mover for meandering. But I still use the fabric mover when I want to do a little fancier free motion.
If you buy one, I suggest getting the stitch regulator too. It's wonderful !