I'm not so sure. The posters may not be biased, but that doesn't mean that the comments aren't. I've seen some ideas that were just not all that great get lavished with praise.

It's possible that I just missed what was so useful about the site in question... but it's also possible that those who didn't like the site didn't comment. I didn't like the site, or indeed care about it at all, and I'm not the type to want to hurt someone's feelings, so I didn't comment on it.

Friends or not, I think the best feedback is likely from users who have the problem you're trying to solve. The best question is probably "why wouldn't you use this thing?"