Disqus and IntenseDebate are both feature rich plugins for WordPress that really amp up the commenting experience on your blog. They both simply and dynamically replacing the normal WordPress comments template with their souped up version, which you are then able to make some customizations to.
Recently, I was working on a client site and they wanted to make sure that users could log in with their Facebook account to leave comments on the blog. We started out with Disqus, and it was a breeze to get going. Then we noticed that the site would periodically timeout. We contacted Rackspace, and tried several different fixes, and finally I decided to deactivate Disqus. Now, I’m no expert in this area, but to me, if I turn off a plugin, and the problem goes away, then there’s an error somewhere in the pipeline. Unfortunately, neither Rackspace, Disqus, or I could figure out why this was happening. It would have been nice to have gotten down to the bottom of the issue, but we really just needed to get things moving along so we could get closer to launch. So we decided to try IntenseDebate.
So far, we haven’t had the timeout issue at all, but we did just so happen to choose them in the middle of them experiencing a strange error that wasn’t letting users change their settings. We contacted them and they let us know they were already on it. We also asked them about how well the comments would sync to our WordPress database. Their email response was more than satisfactory, and I felt like sharing it: