I have no argument with the idea of it being the best. But, my point (that I have stated several different ways in this thread) is wouldn't you rather have someone learn from a hearing teacher than NOT learn at all? I would like to hear from some of the rest of you besides Frisky who seems to want to keep those of us with no access to a Deaf instructor from learning it at all!
Ok, my opinion (remember, I'm not Deaf) is that it's best to learn from a native user, period. If a hearing teacher is proficient (read: incredibly, preferably natively, fluent) and there is
literally no Deaf teacher willing or able to take the position, then it'll do in a pinch. Depending on the teacher, though, they may have ways of doing things that will only ingrain bad habits. Some may sign SEE, some may sign ASL signs in English word order, and some may use excessive mouthing/fingerspelling.
It looks like you're asking from the perspective of a student looking for ASL instruction. My opinion is that, basically, if the person is completely fluent and has a good understanding of Deaf Culture, are certified, and they conduct their classes in a way similar to a Deaf individual, then it will do. However, with the incredible amount of ASL instruction and resources available on the internet, I think that seeking out a Deaf teacher who is able to do private classes or willing to instruct over Skype or ooVoo, is not only better for the student, it also directly benefits the Deaf Community.
I believe Frisky is on about moving ASL instruction from a hearing-dominated field to a purely Deaf field. I'm all for that. I believe that a school should only hire Deaf instructors, who use ASL natively.