We included two PayPal payment gateways in NextGEN Pro, and I wanted to share why. Here is a question that came in from a NextGEN Pro customers:
I set up the e commerce. Sandbox purchases work. I have been emailed to say the sandbox purchases worked. Real ones don't. People can't log in to PayPal when they try to pay. They definitely can log on to the paypal site itself and pay any other paypal customer. It is not a password issue, but it looks like that.
That's one of the downsides to using PayPal Standard. If an end user was logged into a sandbox account or another PayPal account not long before trying to pay for a product sold via PayPal Standard, then PayPal sometimes does that.
We have no control over the PayPal side of things of course, and that is why we also included PayPal Express as a gateway option as well, because it's a far more reliable method of PayPal payment.
Another downside to PayPal Standard is the IPN wait time. IPN stands for Instant Payment Notification and generally it is instant. However, there are times when the PayPal servers are overloaded where the IPN is far from instant. That means that PayPal isn't pinging the store website right away, preventing the same from going through.
PayPal Express is free to setup and use, but just not as fast to set up as PayPal Standard. It's major advantage is using PayPal's API which speeds up the process dramatically which is far less likely to have slow payment confirmations or failures.