I use Paypal not because it's better, I just don't have a reason to Payza. So ask yourself what do you need to accomplish your goal, and does paypal or payza offer that? Then simply choose one, Paypal is more familiar and most people will feel safer when using Paypal because it's universal.
I have been using PayPal since 2008 for all my online transactions, I tried Payza for a few weeks but was not happy with them and also most of my clients were reluctant to use Payza as payment method. PayPal is the best method for all online transactions by far.
For me i use Paypal because it's widely supported and whenever i want to sell/buy something always Paypal is supported in the first place, as for payza it's not widely used, though in fact if i were to change paypal, i would go for Skrill it's much fast, cleaner and cheaper for sure. and doesn't have any support issues or verification issues. but yet it's not widely supported as paypal.
I always seen on thing - Paypal can do bad thing with [email protected] LIMIT you account, eat your money, 100% worst service on help guaranteed = But still you say Paypal is the best.
That is because Paypal has 100s of loop points where you can move your money. 1000s of faults on their API which helps you to run illegal business. You can do business over PAYPAL account. EBAY and AMAZON will help. I see people selling cigarettes over EBAY, illegal medicine most of them are steroids - over PAYPAL. and more and more.
But Payza is more than better. They had faults previously because they are taking over ALERTPAY! but not now.. they are more secure and helpful when you are talking about real business.