How bad is ADD?

I've heard a number of people argue that what's diagnosed as attention-deficit disorder (ADD), is often just boys (or sometimes, and increasingly, girls) acting in a fairly natural fashion that we've decided to call a disorder simply because it makes classroom management a little more challenging.

So, the question should be asked: is ADD really a bad thing?

Consider a blurb from a recent Wall Street Journal Article entitled Bother Me, I'm Thinking:

In recent years, however, scientists have begun to outline the surprising benefits of not paying attention. Sometimes, too much focus can backfire; all that caffeine gets in the way. For instance, researchers have found a surprising link between daydreaming and creativity—people who daydream more are also better at generating new ideas. Other studies have found that employees are more productive when they're allowed to engage in "Internet leisure browsing" and that people unable to concentrate due to severe brain damage actually score above average on various problem-solving tasks. ... In every domain, students who had been diagnosed with attention-deficit disorder achieved more: Their inability to focus turned out to be a creative advantage.

Similarly, in the book The Sexual Paradox, the author notes that:

People with ADHD tend to alternate between periods of hyperfocusing and a diffuse style of attention that goes fishing, casting about for novelty. What is critical is not just coming up with ideas but recognizing if they have currency, and here, too, those with ADHD may have an advantage. One recent study compared a group of college students who reported they had ADHD with a control group. Psychologist Cecile Marczinski found that those with ADHD were faster to react to novelty than those with normal attention spans. The ADHD group was much quicker on the draw when discerning what was new and what was
just the same old thing. (p. 248)

Again, I say, how bad is ADD?