What weight are you using? They recommend 28 wt. for hand quilting, but I dislike it. The ends fray, making it hard to thread the needle, and the place where I've anchored it to the eye invariably breaks before I'm done with the thread length. I would not try to hand quilt with Aurifil 50 wt., it is not strong enough.
I prefer to use threads made for hand quilting, so far I've tried Gutermann and Superior Threads' brand. They are thicker and more wiry than piecing thread.