So while the Quattro sits next to me and stitch, stitch, stitches, the Diamond went back to the shop today. To much bobbin tension one moment and none the next... I really wanted to toss it out of the window, but I'm on the first floor, so no point really. I just took it to a different shop ( Ann Arbor Sewing Center) to see if they could get it right. I've heard good things about their service, so fingers crossed.