My machine is a thread snob too...I found my tension has to be set on 8 and right now I'm trying YUI I think but I have another spool from the quilt store to try. It loves a German brand and I found big spools once and of course I can't find the big spools again only 250 meter ones of AMMAN or AMANN (I'm not in my sewing room). I even called the company to find where they supply it to I'll be making the trip.