It amazes me how often authors seem to use the feedback I give them in rejections as an open invitation for a critique. This is one of the reason that so few agents still give feedback.
You might be surprised by how often we receive emails that go something like this:
I hope you don’t mind an update. I just heard back from another agent who gave me feedback that was very similar to yours. I wanted to send along the first 10 pages again to see if you thought this made a difference. I can’t wait to hear what you think.