I recently used a gold metallic thread from Superior to quilt down a lap sized quilt. Unlike the early metallics, it is not scratchy and worked just fine on my machine with a standard thread on the back. No problems with breakage or knotting or other issues while quilting. I decided on the metallic gold because of the black background of the slightly gold metallic embellished fabric and it also had light solids and I didn't want "scars" of black thread in the pale pinks and whatevers.
Quilt isn't in use yet, but I always wash them after I'm done so just in case anything goes wrong it goes on my watch. It washed just perfectly and dried on hot just fine.
All in all, I'd do it again! Which is good because it was a big spool and I barely used any
