I have only used Paypal. That being said, I have not had issues with Paypal even when issues with Paypal have been reported by others. I also do not like Paypal, but I like it's alternatives less, and I have had my account since the late 90's. Though I can not say for certain I would recommend getting an account today necessarily, though having one can come in handy for things other than just online purchasing - and it is great if you become a seller anywhere (not just 3D but anywhere or anything...ebay, etsy, redbubble, thingverse, turbosquid, etc...).
I think the credit card side of things is greatly affected by numerous factors, including but not limited to: Nation of origin, type of card (i.e. visa or Mastercard), Credit or debit card, specific bank, and actual payment processor for your bank.
One bank I had briefly had problems with all online payments, even those through paypal, because they had particularly draconian anti-fraud policies that basically just flagged every online transaction as potential fraud. It got old fast. I have had more problems with debit/credit cards endorsed by Mastercard as opposed to Visa... but it really depends on the bank they use as authorizer (Elan Financial is horrible as is anything Synchrony). I am in the U.S.
I hope this information is at least useful.
In general, Renderosity is usually good about resolving issues, though in the past years it sometimes can be slow to get a response, but there have also been huge changes in the staff and business behind the scenes.
Most who know me know I will not hesitate to complain and can be unforgiving of companies I feel do not handle business properly - so consider this when weighing what I have said.
