I confirm that it is extremely easy to use, simple but powerful, I use to sell some videos or pdf that I produce.
I can also confirm that the author is extremely active and available to solve any problems.
I recommend this extension.
The author is supportive on his website.
As the component (and addons) is very complex it needs some time to get used to it (at least for a newbie like me), but the learning curve is not so long.
One only minor issue is the translation in Italian, which is not complete and not really accurate, but that's really not important as the product is 100% and well done. :o)
I can help improving the translation if the author needs it.