I LOVE, LOVE, LOVE aurifil thread. For one thing, the weight (50) Is strong yet thin and when you press a seam it doesn't take up any space. I know that sounds snobbish, kinda picky, but my piecing has been so much more accurate since I started using aurifil. And I swear it's like the loaves and fishes story - I use it, leave the room, and there's more on the spool when I get back (okay, I know that's not true, but...) the larger spool just seems to never run out!