very limited,but as you say ,ok for someone with a disability.
but I hope to god they never catch on,as a replacement for the guitar,or that beginners think they can buy one of these and do pub gigs,instead of learning to play a guitar properly.
I find his idea that beginners can pick it up instantly and play, an insult to musician/guitarists ,he clearly has no understanding of the nuances of guitar playing.
however I find the video hilarious