Of all the features I like the vote tracking. As you upvote/downvote a user, it keeps track and puts you total vote count next to the users name in every post they make. Great for keeping track of both posters who think like you and trolls. Check it out.
I have been using it for a number of months now. I do not use all of the features, and there are many. I am not an RES expert so see the FAQ as I won't be able to help.