I was asked this question today in a manner of speaking. Without getting into the details, the topic revolved around some performance metrics – job performance, system performance, etc – it doesn't matter which. My answer – Absolutely!
Metrics, although tough to swallow sometimes, provide great insight and tell a story themselves. Sometimes that story is helpful to your position or argument, other times it's not. Their point is to provide footnotes to the story. They substantiate the fact that you have arrived at your goal or compel you to action. Without them all you have is your gut. Don't get me wrong, at my core, I'm a "gut feel" kinda guy, but metrics are just as important. For example: run down to your local bank and ask for a loan; be sure to explain to the lending agent that you're a responsible person and promise to pay them back. Chances are it won't be enough to get the loan unless the lending agent happens to be your mother.