Needless to say since it is free I gave it a try first. I had several questions and sent a total of 7 emails to the support (some of my questions were already answered in the instructions but I had been too quick and eager to get started and had missed them). However, each email was met with a response sometimes within an hour and never more than 12 hours! I got friendly help each and every time addressing my question specifically.
I do not normally do reviews but felt compelled to write and let you know this extension does the job of adding subscriptions/payments to your site and helps you set up an automatic reply email (where you can include their access details etc) to the new member to get them started.
You should give this a try before paying for a commercial alternative if you want a simple process for adding paypal with automatic member creation to pre selected categories or for multiple purposes.