I don't have a Grace frame, but I know they make a quality product. I know someone who bought one, and she really liked it.
Quilt on a frame is different from hoop quilting - the stitch is the same, but you can't rotate the frame like you can a hoop. So it does take some getting used to.
That said, I love quilting on my quilt frame. It keeps everything up off my lap so I can quilt in the summer, and I don't have to crawl on the floor to baste. I feel I do a better job when I use the frame.
Janet