As a seller, I have been paid, it doesn't matter what the buyer has to say. They did their part. I usually leave feedback when I ship. (unless I forget)

As a buyer, if the 'whatchmacallit" comes to me as advertised, I leave feedback after I've inspected the item.

Anything else is holding feedback hostage and in the end creates a MExican Standoff.

You leave it first... NO you leave it first... No YOU leave it first...

Jezzz, who cares. Feedback is such a minor issue and if someone has a flock of bad ones, you know, they are leaky. One bad one, which we can respond to, or one problem, is such a minor issue.

I'm still waiting for my first Neg. It will come some day. Guess what? I'm already not worried and it hasn't even happened yet.