Bought this when I was learning irish flute. I thought it would help me get that hard low D that is the signature of Irish flute playing. Unfortunately I learned that gadgets don't help with that and only a few years of playing experience has got me to where I want to be.
As with all instruments, the number of hours put into it is the only thing that results in improvements. I should have known as I have played the fiddle for 35 years but I was hoping for a short-cut even though I know there never is one :)
In conclusion, it's a nice idea but it was no help to me in my quest for that perfect tone or blowing angle.