Vijay Singh was once famously quoted for saying that he doesn't look at his swing on video because he'd be tempted to make it look pretty rather than focusing on building a swing that works. This quote is often used by people trying to justify why they won't record their swing or buy a camera.
Unfortunately, Vijay's quote was taken out of context, misunderstood, or was simply untrue. Singh has used high-speed cameras to record his swing for years and maintains a large library of his videos. While practicing, he often has his caddie or others record his swing, and will stop to look at things and make adjustments.
I think that what Vijay Singh was trying to say is that he values function over form. That's fine - and something virtually every good golfer has in common. And while it's true that form follows function in the golf swing, the opposite is also true: function follows form. A high-speed video camera is a useful, valid tool in improving both the form and function of your swing.