I'm a National Board Certified Teacher. I have scored both National Board entries and EdTPA. I lead my district's National Board support program and have mentored over 75 candidates. In some ways they do compliment each other. Both require you to describe your students in detail, set appropriate goals, deliver and analyze instruction, describe and analyze student work, reflect and set new goals. However, National Board Certification is a much more extensive process. Most candidates complete it over the course of 2 years or so. In terms of rigor, I would say they are about equal. But National Board Certification is more extensive. That being said, I found it to be a very valuable process that made me a better teacher and also put me on the path of Teacher Leader. When you are ready, you should consider it!