The Favorit 640 I have sews a mean stitch but you can't adjust the length with out reaching in with a pair of pliers due to the melted stitch length part inside the machine. The inside has some plastic gears - maybe nylon even then, it weighs a ton. The bobbin loads in the back so is awkward to use. It is in a case so it is supposed to be portable. LOL... I had a Bernina 530 for a while - it was all locked up and there was not much access to the innards to get it cleaned up. The knee control was missing and nothing else worked to make it run. If I were to judge all Bernina machines by those two I guess I would stay clear. I don't go out of my way to get a Bernina. I know there are people who love them I do not. I think there are simpler machines that will do the job and be easier to maintain from day to day let alone major work.