I can't understand why anybody would use standard satchels when C&S is cheaper and safer. As long as you have a printer and are prepared to spend $1.25 for stock.

A big advantage, as said above, is that you can't put a non-compliant address in. Apart from the suburb/city I've had incorrect postcodes, wrong suburb (and that was to a business address. Luckily the business knew where they are located, according to their website, anyway), so regardless of Paypal I prefer to send goods to where the buyer is, rather than where they think they are.