What i do for balance is give 5/5 if everything shows up as expected, and just write a bad/truthful feedback in the text area . I often write long winded detailed feedback , but still turn around and give 5/5 . So you get to rant and still not worry about getting blacklisted or whatever. The detailed feedback gives the vendor something to read and work on and other customers can learn a lot of what happened and not be scared off by a low rating.  I think people leave too little of text in the feedback for others to read from.