Perfect for our non-profit

Our website is for an environmental conservation group. None of our transactions are for actual products. We reserve picnic tables and tents, register for childrens programs, or sign up for membership. WP Express Checkout has all of the flexibility that we need. For example we offer a member discount for some services, for which we use “coupons”. Quantities can vary (3 picnic tables, 2 children) which is easily handled. We use WpForms to collect the personal information, and directly below the form we use a shortcode to add the WP Express Checkout payment for that “product”. Our users seem to find this fairly intuitive. And our treasurer is happy with the PayPal interface. Confirmation emails go the the customer, to our general email, and to the treasurer.
The support has been terrific. I submitted a question about the default country code, and received a response within hours.