Morse training in amateur radio has too many experts and not enough professionals, I am continually finding this out much to my displeasure and frustration. If you consider the amount of money it costs to train a professional Morse operator, they will have been taught using the quickest and best methods to get them up to standard as soon as possible.
In 1965 I was taught Morse in the RAF using the Farnsworth / Koch method, I did not use any visual aids, slow Morse or any other method and was doing 20wpm at the end of the course. I like to offer students the same excellent tuition that I had.
In the 1980’s it was deemed a good idea to bring the standards of the Aldus Signal Lamp to amateur radio with the introduction of the 5wpm Morse Test. Today I am still dealing with the fall-out that slow Morse has caused, being detrimental to the learning of good Morse and which can seriously prevent the student achieving a decent standard.
90% of websites promoting Morse can be detrimental but 10% are good so choose carefully before starting on your journey so you can enjoy it and not end up pulling your hair out.