Reputation matters. When your looking for someone to add to your team, reputation is your best indicator to how successful they will be for you. If your a technology professional, your reputation defines who you are and what your good at. Don't leave something this important to anonymous comments!
Reputations based purely on user feedback never tell the whole story. Just a quick glance at amazon's mechanical turk will show you how easy it is to game feedback-based reputations. A real reputation is based on experience, not just comments. Of course feedback is important! Communication, participation and how well someone works with others are critical components in how they will work with your team. CoderTribe's reputation engine uses multiple sources of information to calculate their score. What they have done, who they did it with, and how they did it all factor into their score.
Reputations aren't static. A person's reputation changes over time. Projects they take on, communities they participate in, how they present themselves to the world all have an impact on their reputation. Context is also important. A person's reputation for blogging may be strong, but that doesn't mean they can build your next iPhone mind-reading application. CoderScores are based on what you are looking for.