Different philosophies... Having been taught many "learning devices" (especially for guitar) ... I wish I hadn't.

I've taught/teach many subjects (swimming, guitar, electronics, software design, flying), I comprehend that people learn in differnt ways and have different goals. I've developed the philosophy that the correct method is always preferrable to short cuts. It may take a little longer but, later progress is not hampered by the much more cumbersome 'un-learning' process, particularly where 'motor skills' are involved.

Not trying to be argumentative here, I just feel that students ought to be well informed of the true cost of short cuts so they can make their own decision.