I have a mechanical Elna 634 bought some time ago. I love it. It is perfect for what I want to do and didn't cost an arm and a leg! I have used it for napkins, placemats, edge finishing on trims for bags and to construct simple summer garments (capris and skirts). Oh, and pillowcases, too! The threading is color-coded and very easy. I have used it in a class for simple patchwork piecing, but I wasn't happy with my results, so I use the regular sewing machine for that. If I were shopping for a serger, I would consider what I wanted to use it for and try out many different types at the dealer. I might also bring my own fabrics to try them out. JMHO. Good Luck on your hunt and have fun!