Clearly people who are genuine teachers, with proper education degrees and classroom experience, are preferable to those who are not qualified as such.

China has a high number of foreigners teaching English who are not qualified, not to teach or from my experience, to hold any kind of professional job even in their own home countries. There are truely alot of wankers working in this country, and a good number of them reguraly post on these pages I suspect, judging from many of the things I have read here.

The question on this link however is about Native as opposed to non-Native speaking teachers. Assumming we are talking about experienced teachers, I agree with some of the posts above that there is absolutly no question that native speakers are much preferred and serve their students better.

Any language student would want a native speaker teaching them as opposed to someone speaking as a second language. I agree with all of Leonardo's points above.