Is there any hard cold facts (written documentation) that any brand of sewing machine from a big box store is actually made differently than the same machine from a dealer store? Of course dealers would say there is a difference and of course big box stores would say there is no difference. But is there written proof anywhere or is it all hearsay? I am omitting the service factor you get from a dealer. I just mean in how they are manufactured and the quality of the parts.