I have the L500--have had it for 2 years and use it everyday without any problems. It has a 8 5/8 inch throat space, built in walking foot and I believe it sews 1100 stitches per minute. It does not have a stitch regulator. I'm just learning to fmq but it sews a great stitch when I can guide the fabric correctly
. I can't speak to other machines, I just wanted to let you know of my experience with my Singer.