The problem with not leaving it is that it leads to feedback nags.

A buyer actually told me I was a bad seller because I took more than 3 days to leave feedback for them . . . they sent me something like 5 messages about it in 3 days. At that point, I didn't want to leave it just because I was so annoyed, but they were SO angry about it that I thought they might neg me if I didn't.

So I left it for them and then blocked them. How's that for "feedback"? ^_^