It's very feature rich and also good looking.
You can have individual settings for every usertype, which is very useful.
And also a report function for comments.
The support for custom BBCode is very good too.
It enables you to create your own buttons for any video site etc to embed videos in the comments.
A Youtube button comes as default with the installation of JComments.
The only thing I miss is an "IP ban" feature. But I saw it's coming in a future version.