I agree with others who have advised you to actually deal-- hands on-- with a serger before purchasing. I was given a very expensive 5-thread serger years ago and it was such a beast to thread that I finally traded it for a Babylock air threader. Never been sorry for that trade. Also suggest that you get some training in using your serger. Makes a big difference on how and when you use it. If you have a local dealer, check with them on your options as to machines, as well as classes, etc.