Hi there. Thanks for a great plugin!
I'm the author of the s2Member plugin, and we are planning to refer some of our clients to your plugin.
However, I was hoping you might be able to provide the ability to edit Capabilities on a per-User basis? This is possible internally, but I've not seen a plugin that makes it easily editable. Perhaps a tool in the User Editing Panel for WordPress?
If you can add this feature, please let me know. I'll be willing to make a donation toward it's development.