PayPalSucks.com is a webpage about how bad PayPal is. It lists all the main reason for why it sucks and a forum (well used it looks) for peoples own horror stories.
This can't be good for PayPal. Maybe the page is secretly supported by one it its rivals. Or, some smart ass sets the site up and then expects a large donation from PayPal corp. for taking the site down.
At work we used WorldPay, and the only bad thing I've found about them is this piece about the customisation