I used them for about 2 years.
No problems. Timely payments.
Setting up with them takes forever, but they're pretty good
overall.
I never had a chargeback, and if I did, they took the heat for
it.
PayPal is best, but they'll reject a lot of payments from
various countries. 2Checkout and ClickBank are both
good and reliable (2checkout charges less processing).
Good luck.
Luc L.