For many people, this might seem like a frivolous instrument, but it really has many uses. For one, it gives the user a better picture of what is happening inside that circuit. As any doctor will tell you, the x-ray helped doctors immensely, and this instrument is much the same. I have used similar instruments to analyze circuits that cost thousands of dollars, if someone is willing to spend that kind of money to do what this instrument does for a very small fraction of that upper cost - then why not use this one.
WELL WORTH THE INVESTMENT!