There are a lot of upsides to these kinds of plugins/addons, given the right community, and given that the administrative staff can administer it properly. There are also a lot of potential downsides. I for one, at most forums I visit, have terrible rep, which annoys me, while post-whoring morons have rep up in the thousands. I've never quite understood how this can happen. Example (this is paraphrasing my experience on some other servers):
Me: "Hi, I'm new to the forums. I just signed up. Nice to meet you all. I am intelligent but because I'm not a regular, my rep says I'm a "shit eater". I read through the FAQ and I read your recent post on blahblahblah. I would like to disagree on a few points and bring more information to the table.".
Post-whoring regular troll with rep 10,000: "Blah blah blah, all shit is coming out of my mouth, but because my rep is so big and I'm a regular here, I have lots of starts next to my name and people respect me even though neither I or those people have any clue what they are talking about."
Other regulars: "Yeah, we agree with post-whoring regular troll. He's been here longer than you, new user, and look at your rep! We don't know what we're talking about, and since we don't know, we'll just agree with troll and give him some more rep, because we like watching him give the smack-down to noobs like you"
In other words, rep is dangerous under the wrong circumstances in that it can breed an entire tribe of a morons on your server.
With that all said, maybe we should give it a try. Also Jets mentioned the thank-you plugin to me about 5 minutes after I launched the new forums lol. If you guys think this would improve the quality of the user experience in the forums I'm willing to give it a try? So long as I can find a reliable plug-in for VB (even if I have to pay for it) I don't want a flimsy, unsupported open-source plugin that is going to leave a gaping security hole in my server.