The Babylock Protege is a good serger. At least mine was. I bought it in the early 90's and it is very easy to operate. Sometimes it is hard to thread the loopers but probably no harder than any others that are not jet air threaded. I would usually just tie on when I needed to make a color change.
I upgraded to the BL Imagine Wave in 2006 because my eye's just aren't what they used to be! My youngest DD now has my Protege and it is still going strong.