I sew for a living and business has picked up so much that I've been thinking of getting a commercial grade machine just for the speed. The machines I am using now have a maximum speed of 850 stitches per minute. I looked at a couple of Singers that go up to 1100 SPM which doesn't seem like much of an increase in speed. There is a Brother that is tempting at 1850 SPM, but it only does straight stitches and I need at least a zigzag. So ... is it worth it? Any ideas? I primarily sew lace, nothing heavy like denim.