I processed with PayPal for nearly 2 years until I switched to CCBill. I had 1 chargeback via PayPal and they decided in my favor
I'd say maybe 4 chargebacks or so since I've switched to CCBill late last year, which is annoying as I never got them via PayPal. Could be credit card statement, people forgetting or something - who knows?
CCBill is also annoyingly anal about chargebacks. All you have to do is say "I'll do a chargeback, I don't recognize this charge" and they'll refund your purchase immediately. I can't count how many refunds have been issued to customers who contact ccbill about stupid things like username/pass problems, forgot login link, etc - and CCBill just refunds their money like it doesn't matter. I get no notification of them doing it, then I have to contact them to find out why they refunded their money. Total BS if you ask me. If someone pays to join my site, joins it, rips the content, then complains - don't refund their money. Fight the chargeback.
I remember doing some mainstream stuff and worked with a company who charged customers $250 extra if they initiate a fraudulent chargeback. Needless to say they never got any chargebacks and the ones that did were just fraud. They also got around refund rates by not issuing a refund and issuing a paper check through the mail.