They absolutely do fill that indispensable role. There I times where I wish the knowledge was etched in more permanent documentation that didn't require quite as much digging. This wish is particularly true when a thread has useful information spread throughout a few hundred posts, not just at the top. I know most people are good about keeping the first post updated, but it's asking a lot sometimes.

Yeah, I'm picking nits, because Ubuntu is by far the best distro (and OS) for available information and support.