The 37 is a standard ¼-inch foot. The 57 has an edge which is used as a seam guide.Personally I'd get the 37; it's accurate, you just line up the edges of the fabric with the edge of the foot. I have used one of these edged feet on a friend's machine and it's fine for piecing until you have to join more patches. It won't ride easily over untrimmed points - so you'd have to trim as you go or get the little 'ears' pushed into the seam.