Remember, half a dozen years ago or more, when National Board Certification was the end-all, be-all for teachers? Well, Diane Ravitch has some concerns about what's become of National Board certification--which indicates to me that I was probably correct in dismissing it.
Notice how nobody pursued it once the stipends for it went away? There's a reason for that. No one thought it valuable enough, as a professional, to pursue unless they got paid for it.
Now I know that some reader will point me to some report somewhere that showed that National Board certified teachers are better, stronger, and faster than the rest of us. I've read several of them, and my biggest concern with each of them was that they seemed to get things backward: it's not National Board-certified teachers that cause students to do well, rather it's just as likely that teachers who were good already (or who were willing to jump through the hoops and do the required dog-and-pony show) sought out National Board certification as another feather in their caps. I haven't seen any definitive links between pursuing NB certification and improvements in student performance.