One thing I miss about the birdsite was the ability to boost with a comment. I know it was abused to mock, but it was also handy to direct users to a thread with particularly insightful comments.

I hope people realize that when I boost a random comment in a thread, I'm saying "This was a good thread, and this particular person was particularly insightful (or hilarious)". Because a lot of them need the context of the thread to be fully grokked.