There is paid support if you need it, which I did as I had a problem with another plug in, however the support is excellent and very helpful and very speedy.
The comment system itself is a breeze to use and install, with a tremendous amount of options. It has a very smart looking front end (and back end) with nice roll-over graphics.
Please be aware that it does not support vBulletin avatars as listed above. The developer advised me that this was a mistake when documenting for Joomla extension.