13. USF really doesn't get off the ground below 1500 points. You can do it, but the sweet spot is actually 2000 points and over. USF is one of the few Eldar army lists (hell, one of the only lists period) that continues to get better between 2000 points and 3000 points. But below 1500? It's hard to turn the engine over. It's too expensive and resource-heavy to make the magic work at that point, so switch back to Ulthwe or Vanilla at that point.
I feel better now.