When I was seriously shopping for a machine for our daughter for a high school graduation present, one VIP point someone showed me was how the machines lay the stitches on the cloth.
My singer laid them one in front of the other in a precisely straight line, while some other machines laid stitches slightly diagonal to each other. I had never noticed that before, because I did not own one of the cheaper models. But when they pointed that out to me, it was very obvious.
It seems to me that all machines could leay stitches straight if they would, but they don't.
GramMER