From May 13th, 2013 to July 30th, 2013, 50% user give 5-star rating, 50% user give 2-star rating. for PeerReach chrome extension.
It seems that this extension, while being quite good, more often triggers account suspension. I'm still looking into it, but at face value it apparently it looks to twitter like invasive network activity.
Finally. Now you know who's worth listening to in your Twitter stream.