I have pieced with JoAnn's cone (serger) thread for a long time. I have had my Bailey Home Quilter to almost 4 years and it uses the same thread. I have never had a problem. I make a lot of charity quilts and do not think the more expensive thread is necessary. I also use sheets on the backs of my quilts and that is frowned upon by some quilters. If I were making heirloom quilts, it might be a different story. For me, thread is thread.
June in Cincinnati