The BabyLoc is the cadilac in threading from what I hear. Any serger in good repair can work, some with more and some with less elbow grease involved on the operator's part. I sat in on a class recently where a quilt as you go sandwich was made. I wore my Singer U234D out several years ago after many hours of overuse. LOL I am trying to save enough to purchase a new machine, probably a Bernina.
The strips to be quilted were layered so that they opened out after being serged with the serged seam inside.I am going to try to replicate the technique with my home sewing machine.'