I have quilted 4 quilts lately on my Bernina 200. With using basting spray and safety pins about every 4 inches , I haven't experienced any problems of shifting, etc.
I use the bicycle clips and roll half of it up and start in the middle and quilt to one end. So far, I have only done SID and quilting an "X" in squares. The largest I have quilted is 48"x68" for a charity quilt.