In reply to Mike Schinkel.

Thanks for asking that, Mike. I think it would help this thread, and a few others in this conversation, for folks to have a clearer understanding of our different products.

We make 6 different native commenting plugins, all of which can be mixed and matched to make the setup that works for your site. Four of them are free. One is freemium (Replyable) and one is fully commercial (Postmatic). All are GPL. You can read about them all on our site.

Then to complicate things a little further, we do everything we can to make sure our plugins are compatible with other native-comment based plugins for even more flexibility. That's where things like Simple Comment Editing and Basic Comment Quicktags come in. Neither are made by us but we all use the native WordPress comment system as a central backbone.

Now on to your question.

The two plugins which users may upgrade/downgrade/switch between would be Replyable and Postmatic. There are features in Postmatic which are not found in Replyable. However, there are not any features in Replyable which are not in Postmatic. Replyable is just the most-used feature of Postmatic (email comment subscriptions) abstracted out into a standalone plugin. You can read more about our decision to do so on our blog.

Based solely on price point we're going to guess that users first become familiar with our technology through using Replyable. If they then think they want to leverage the fuller engagement package which is Postmatic, they can upgrade to it easily. Or, if Postmatic users want to downgrade to Replyable that is possible as well. The big question our users have is this: If I switch between Postmatic and Replyable, what happens to existing comment subscriptions? What if someone sends a reply email to a comment that was sent from Postmatic, but now I use Replyable? The answer is that the emails will continue to be routed just fine. Switching is seamless.

I'm happy to answer any other questions you might have.. but if you want to follow up with me directly you can do so via our site.

Thanks!