We took a fair amount of time to review similar products and found Membership Control by OSE to be THE BEST !
It is the most recently updated, the furthest along in version updates and iterations, and had more features we needed out of the box than any of their competitors.
Furthermore we needed some customizations, which Helix and his team took very personally, they got themselves into the trenches with us and delivered all that was requested in a timely and attentive fashion.
It is obvious to us that they worked very hard on our project, even working after hours to help us meet a deadline that had nothing to do with them.
Finally I want to add that when we requested support from their competitors during our initial evaluation, many didn't respond at all, some responded within 24-72 hours, but Helix and his team responded the same day !
We are anxious to use them for other customizations and recommend them highly to you as well.
Thanks Guys, You give yourselves and your company, and the open source developer community a great reputation, and hope that open source development doesn't have to be as difficult as some make it seem.
We can't thank you enough.