I have the one for Viking w/Stitch Reg with the larger opening. It works llike the Bernina in that the stitch size is the same no matter how fast or slow you move the quilt/platform. However it can be over done with extremely fast movement and the stitch is then larger. The weight of the quilt is on the platform and easier to more than regular FMQ. I used it a lot but now that I have more experience at FMQ I use it only if I want REALLY even stitch length. I personally cannot see any use for a Fab-U-Motion W/O the stitch regulator. That price seems incredibly low if it DOES have a SR.