I wish I could say that I am using an 820, but that would be a dream. I cannot complain, I have a 630 and love it. About the BSR, remember that the machine is not only going to sew as fast as you move the fabric, it will also move at a speed related to the desire size stitch. I suggest to reduce the size of the stitch to 1.5, make sure the needle is not dull, and hold the fabric tight, on both sides of the needle. I like the BSR set on the setting where it only moves if I am moving and stops when I stop. Keep on practicing. Is the only way you get used to it.