I spent over 1 month developing a proper membership site with WordPress. Here are my findings but please note I have no affiliation but posting for info purposes only
This is a real piece of work. The software is really useful for techie people who like working with short codes and PHP. I would recommend this for anyone ONLY interested in this area. As for the usefulness of it, forget it. If you want a FREE plugin, go for it but I found it a big time waster. After the purchase of the S2Member Pro, I found their Priority support is utter rubbish. All they do is queue the support query list and work from the oldest. As a result, my queries were lost for 48 hours which resulted in virtually no useful response to resolve any issues of the plugin. Out of frustration, my team decided to scramble looking for an alternative so see below. My general thought is this vendor are nothing but scammers who care only about $ vs successful implementations using their software. They do not offer any refunds on the product which clearly shows how they stand on their product. They are quite confrontational when this is pressed. In summary, this is easily the worst online vendor I have worked with in the last 10 years. I spend thousands a year on various plug-ins, themes, etc but I am out of pocket with this software. This is my only worst experience ever with any online vendor. As a result, be careful if you decide to use this software. You have been warned!