Filed by myself, I140 (NIW) was approved in 2 months. Points to be stressed:
1. Reference letters: prepare different reference letters from different points of your work, don't need to over-stress how important your work is related with the national interest.
2. Personal Statement: Boast yourself as much as you can:))).
3. Arrange all your materials in order.
4. Don't leave some important supporting materials.
I will start my I485 petition now.