I make a habit of not paying personal, but that's not because I've been burned by it, it's because it's one of the potential indicators of a scam. Obviously if you know the person or have done business with them in the past, then it's your call. You have recourse with PayPal when it's for goods, when it's personal, PayPal has no legal reason to back you because you could be just giving someone money.
Just friendly advice not a hard and fast rule. The more and more we do business over the internet, the more chances there are for scams.