I've had PayPal since 2000, and have only had one problem with them. In the wee hours of the morning, I made a large purchase at Amazon using my PayPal debit card. PayPal called me the next morning to verify the purchase since it was out of the norm for me. Somehow, later that day, the card was closed for fraud reported and my Amazon order did not go through.
As an apology, a customer service agent at PayPal issued me a $20 credit to my account for my trouble. I was a little perturbed at my order being delayed, but pleased that they even monitored transactions like that. Also, the customer service peoples were all friendly on the phone and worked with me to figure out what happened and resolve the issue.
I've never had problems receiving money. I do wish one of the MSC's I work with would lump all the little jobs into one PayPal payment come payday instead of making individual transactions for each one. But that's not a PayPal issue!