I agree with glassnquilts. I don't even do much 'freehand' but do like the quilting part. Another thing that has made me not want that as the others have said, if mistakes happen and you aren't watching (isn't that when ALL mistaken happen?), you aren't there to catch them. I saw a quilt in a quilt store; was on the frames and had the computer and all set up; it had quilted across the quilt but the entire center part hadn't gotten quilted. Going back and doing that over would not be a time saver.
Personally I'd rather have the system that I've seen in Nancy's catalog where you can 'view' the underside to be sure the bobbin threads are even and not looped. Good luck with whatever you choose to do.