I was very happy last year using Superior's Metallic Gold color. I used it to quilt down a lap quilt with rather thick batting and I expected a lot more troubles than I got -- which was none. For that I was doing a large free motion meander with a BSR (bernina stitch regulator).
I also personalized my hubby's bowling rags with a Todd Todd Todd border using that same thread, again, zero breakage.
Today's metallic threads are not the horrible things of the 1980s!