Have you added Amazon payments as an option as well? I would choose that every time, given the choice, if for no other reason than Paypal is always trying to trick me into paying from my bank account, when I really want to pay with credit card for rewards and security. Amazon doesn't try to trick me.
Universally, on all of these sites, customers choose to pay with PayPal more often than credit card. For the most part, my payment pages are a secure credit card form with a "or Pay with PayPal" button to the right of the form. More people choose to click through to PayPal than to just put their card in to the form already on screen.
The preference for PayPal is larger outside the US among my customers.