Personally, I would pass on the deal. Serger thread is notoriously not a strong thread for regular sewing. It is meant to close seams, having 3 or 4 threads interlocking, giving a strong seam. But using it for a single seam isn't a good idea. I use 60 wt for my bobbins when doing embroidery, which is what your thread is listing, 60 wt. 3 ply. I know nothing about the left twist. For my quilting I only use top quality thread, Aurifil, YLI, etc. I figure my work is worth the best I can afford. They are low lint and very strong. My machines seem to prefer cotton thread.