Native or non-native: who's worth more?

A s the other articles about the native speaker, this article also made me think about native speaker again with problematic wiews, and it's more interesting to me that dichotomay in ELT.
While reading several articles including this, the idea about the native speaker has changed.

Edge's view that all users of English are simultaneously learners of English reduce my burden to English study. However, I really agreed the other's claim that for all thier efforts, non-native speakers can never achieve a native speaker's competence. When one of my daughters asked me dicatate some words from her list for spelling test, there are so many words that I don't knowd the meaning. The words are for elemetary school students in America. So I realized I have learned taught very narrow spectum of English (for International or broadcating English).
I really agreed that one of the most professional duties non-NESTs have to perform is to improve their command of English and it's also true that teacher's learning process is impeded by several kinds of constraints. I have a similar experience in Korea. I want to study English more for my fluency, but I don't have time to do. In high school I had too many classes a day and sometimes we work over 9 pm.

A few years ago, In Korea president Lee said "Egnlish teachers must teach English only in Englsih and Korean edcation department will hire more and more native teachers who will replace the korean English teachers. But I certainly sure that to teach English effeciently to L2 learners, both teachers are needed through my experience with native teachers. And speaking is not the only thing to teach. One of my friends worried me saying "Maybe you may lose your job as an English teacher, and Korean Enghish teachers may disappear in schools. So I answered very firmly, "Don't worry. Non-NESTs also have many constraints in our education system.What you worried will not happen". Until now there's no change in Korean English education system, but to me there's big change "I'm in America for my English study"
It's ideal that we try to find good balance of NESTs and non-NESTs who complement each other in their strengths and weaknesses.