Going on two years with no paypal or ebay problems. This always becomes a hot topic pro vs against paypal. They do the best job they can. One weak area is service and eletronic files(softwares and templates). This is mainly because both were created for the sale of physical goods. I do believe paypal & eBay are working on getting better.

I havent had any problems with either....
Apart from the paypal support taking a VERY long time to reply, support is one thing they really need to work on I think