One reason I bought my red machine Bernina (215) was that the motor was supposed to be heavier duty and yep, so far it has stitched just fine, but I really haven't done much heavy stitching with it. When I traded my lemon Bernina 570 for the 590, which is also supposed to have a more powerful motor, it really does seem to be a sturdier machine, but then again, the 570 was a lemon. My old Viking D1 (RIP) was a workhorse, and when my other machines would have a problem (like making pleated curtains with pleating tape 6 thick layers), that is the machine that would plow through it. I think the machines with metal parts including the insides are sturdier than the plastic ones.