Missi,
I am on my second Bernina serger. I purchased a cheap serger, some oriental brand when they first became popular. It was a piece of junk. I spent more time cussing at it than sewing. Then I purchased a Bernina. It was about the middle of their line. It had differental feed and a built in rolled hem. I used it for years. Just earlier this year I got the thread tangled up really bad and actually broke off one of the loopers. I took it to the shop for an estimate. I decided to trade it in on a newer model. Again not the top of the line but it does have functions that make the threading easier as well as differential feed and a built in rolled hem. It also has a needlethreader built in like most of the newer machines. I have one on my embroidery machine, also a Bernina, but I prefer to thread the needles myself. I got the Bernina 1150MDA for about $900 less the $150 they gave me for my trade in. They will repair it and sell it to someone else. I love the new one. I have always done piecing with my sergers.