I installed JComments at a Joomla 1.5.21 website.
I was pleased that the configuration page showed up right after install.
I like having each configuration option briefly explained right on the form.
This is the first commenting tool I've installed. At my client's website, there is a page for each of four books, and we want visitors to be able to comment on each book. JComments seems to have everything I need. The main feature I wanted was for the website owner to be able to moderate the comments, and that seems to be really easy, especially with the moderation links right in the notification emails.
I also like the ability to set permissions by user role.
I'm an intermediate Joomla web developer.
We decided to let unregistered users comment. If we had wanted to restrict comments to only registered users, JComments would have let me set up that too.