I buy and sell fair bit of stuff through Ebay, always use PayPal, don't buy if its not available. It gives me and the buyer/seller a measure of protection from fraud. Don't mind paying the fees.
Never had a problem with delayed payment on either kind of transaction in USA, UK or here in Aus, but I've never dealt with China (apart from Hong Kong). Any items I've sold/bought with paypal payment the transfer has been almost instantaneous.
Robert, the advantage of the registered post is that there is a record of the goods being shipped, and of being recieved. "In god we trust, all others need a paper trail"
Bill