My friends ALL have been piecing with Aurifil. I still am using what I was told by the Bernina dealership over 15 years ago to use Mettler Silk-finished and that is 50/3. I too am on board that 35 weight thread is to heavy for piecing.

I used Mettler silk-finish cotton thread in my Bernina for *years* -- until I tried Aurifil 50wt 2-ply. That was it for me. Aurifil is soooooo much nicer!