I tried to buy XenForo and the resource add-on last night and my credit card issuer will not permit purchases using cards they issue through PayPal. I talked to their Risk dept and they told me their policy was to decline those charges. I had to use another card to make the purchase.
I have a vBulletin 5.05 community I am planning to switch over to XenForo. Tired of long promised features and updates that break current features.