After weeks of developing a site with s2member and setting up the 100 options, it randomly at 6:30 this morning wiped out all of the settings. EVERYTHING. Like a completely fresh install. This plugin is dangerous and I don't recommend it at all anymore. At first I thought it was a legitimate, solid plugin. Now I realize I was 100% wrong about that.
If you happen to have this piece of shit plugin installed, you'll probably want to make a backup of everything. And export the settings. Just in case this plugin decides to do that to you also.
I used to like s2member for basic membership capabilities. I needed some more complex membership abilities including authorize.net integration. So my client purchased the 'pro' version. BAD decision. I thought because the basic version seemed so solid that the pro version would also be solid. Many of the pro features just don't work.
s2member Authorize.net for more than one website (Authorize.net Central IPN)
They provide a 'sample' file for you to use to be able to fork the silent post responses to more than one website. It does not work. I tried to get support for this and it was 100% non-existent. They don't provide support... period. So I ended up creating my own authorize.net central IPN to get that working.
s2member Feature: ability to sell individual posts
Then ran into another issue. When trying to 'sell individual posts', the functionality is all screwed up. They get directed to the membership options page and there is no indication of what you are purchasing really. So you think it's allowing purchase of a single post, enter the c/card into, and find out that you just purchased an annual membership. The plugin doesn't seem to be able to differentiate between a post/page for sale and a recurring membership.
Anyway, bottom line - DO NOT PURCHASE THE PRO VERSION!