In early February, I saw a post on an agency blog I follow. The agents were running something called 'Slush Week.' Writers were invited to send their queries, with the chance of having one of the agents review it.
I did the dangerous thing and sent mine in. In the intervening weeks, I changed it completely. (Thank God!) It got to the point that I was praying that my old query wouldn't be chosen. But you guessed it. It was.
You can view the carnage here.