Re: XPaymnet and PayPal Advanced
PayPal Advanced includes many different PayPal solutions. X-Payments supports PayPal Payments PRO. Other PayPal solutions are in X-Cart.
PayPal Payments PRO is needed when you want to accept credit cards on your web-site pages ("merchant hosted" type of integration) and do not want your visitors to leave your web-site for payment.
VP of Business Development for X-Cart