I dislike PP's policies, but they're easier to use (IMO) than Google Checkout. I don't know about Google Checkout, but PayPal is very quick to freeze accounts with 'suspicious' activity. Then, from what I've heard, it can be near impossible to unfreeze the money.
Suspicious activity tends to be actually processing a lot of payments.
+1 I used a VPN connection once to make a payment and they called me at 2am the same day to let me verify that i made the payment. Short after, they froze my account for no real reason. Did not lose any money but i dislike their policies much. They are much too restrictive. Sad, because the idea behind PayPal is good and payment works without problems (when it works).