Feedback can be a vicous thing. As a seller I would never leave feedback right away, especially if you accept checks or paypal as payment. My parents have adopted the wait until they recieve a positive until they leave it belief as a seller because of a couple nasty situations. They had one buyer that paid by check. They waited 14 days, sent the item and left + feedback. On day 20 they got the ISF notice from the bank. The buyer already had his positive, and the item. He refused to pay their NSF fee. Another buyer paid via paypal and had buyer's remorse. He told paypal that he never recieved it. Paypal refunded his money even though my parents had emails from him saying he got the item. They had already left positive in this case as well.. Like I said in another post, feedback is overrated.