The insides are different from one machine to another - some have metal camstacks with gears and some are more simple and some do have plastic cam stacks. Some just use cams with readers. I can remember the sewing machine guys warning people not to buy Japanese machines. I don't know if they were prejudiced because of the war or if the machines weren't as good as the others. Then in the 1970s they were saying only the European machines were any good. From what I have seen - I would prefer an old European machine than some of the Japanese I have looked at. But we are talking big bucks differences in some cases. For just straight sew or zig zag the Japanese machines are just fine and do an adequate job. For the fancy stitches I can see why you would go with European. I am not at all impressed with the newer plastic and stamped metal machines. I think they are not built to last any length of time and don't do any improved job of sewing. If you figure 95% of the time you are sewing straight stitches it isn't all that important to have the fancy stitches. I've had people lately buy a machine because it just does straight stitch and it is cheaper to get one than to take an electronic machine in to be cleaned. They can clean the vintage machines themselves.