I think that all the machines today will have some plastic in them. I do not have a digital machine (computerized) and the two that are relatively modern are a combo. What is important for me is that motor is in metal housing. I have Singer 5050 DSM and it's European slightly different version. My serger is brand new an I believe it is all plastic. I use it way less than my machine so it was not an issue. If you are talking longarm machines I have never handled one so I have no idea. I do dislike plastic, it seems that's the way the production is going these days. Which one is the best depends on the user and her preferences. Good luck.