I was hesitant at first; eventually I followed the instructions, and it did what it was supposed to do.
I was a bit alarmed when there was no confirmatory message saying the stock tune had been preserved, and nothing to indicate the new tune was in effect.
I've done and undone all the b@m@achips tunes a few times by now, and the machine's performance has been flawless. The custom tunes make perceptible and measurable differences. Money well-spent, my view.