As for your story about the MacBook Pro.....this is exactly why I say they are no good. I would even go so far as to say they are plain evil. The worse part about this is that the other person probably never saw the money in their account. PayPal used it as an excuse to hold the money in their accounts and make interest off of it. Now, granted the amount of money that this amounts to for just your transaction is minuscule; however, if you figure there could be a million disputes at any given time, this adds up very quickly.
I'll briefly summarize. Sold a 2012 unibody MBP for like $1,300.00. Guy pays. Fine. I ship with insurance, signature confirmation and delivery confirmation. I mean the whole nine. Guys emails me saying the computer was a mess, dirty, filthy. Mind you, the thing was immaculate, I sold it after only several months to get my rMBP.
So he then files a claim. Without even really hearing my side, PayPal sides with him, and tells him to send it back. At this point, PayPal takes what money I had in my PayPal account and freezes it, then reduces my PP balance even further to meet the computer total. So right now I have no computer, have a PayPal account balance of -$1k+ and I'm not feeling great.
So all the guy has to do is tell PayPal the tracking number when he ships it back. Now it's my turn to tell PayPal when I get the computer back. Well, I went to pick up the computer at the PO as I wasn't home, and the girl brings me a large envelope, with the tracking number the guy gave to PayPal/eBay as the return. The thing weighed about 3 ounces.
So I call PayPal and tell them I was just defrauded and received an envelope with nothing in it from "John Smith" and that I want to escalate this claim as fraud. You'll never guess what they do next... since I did get the package the guy sent back, they sent him his money back, then they initiated my claim. Did you read that? I just told them I got an empty envelope back, and rather than thinking fraud, they paid him back, and then dealt with my claim. Brilliant.
So I had to get a police report, fax information, go to the PO, it was a nightmare. The police almost laughed me out of the station, until I went back and spoke to a very nice officer who pointed me to online forms for the PD.
This went on for the better part of the summer, I kid you not, as it took a while to finally get the police report. Even after that, they were still "working" on it, until I sent a letter to their corporate headquarters and their resident agent for my state, I then got a phone call. Within 72 hours, they put the money back into my PayPal account, and at least gave me back all PayPal receiving fees.
So in the end, the guy ended up with my computer, his money back, and PayPal paid me back the money he took back. Theres a business model.