I took the time today and installed the plugin here on my feed and am, so far, loving it. It is a very powerful plugin and seems to do everything that it advertises. Though I am not using the IP identification tool due to my use of FeedBurner, I am using it to place a small copyright notice and the digital fingerprint.
It also corrects other feed-related issues, such as WordPress artificially truncating entries that use the “MORE” tag, and adds the ability to insert comments and related posts into the feed.
The only frustration I’ve had is that you need to be careful to save your options before you update the preview, otherwise, you will likely lose all of your work.
Beyond that, if it works correctly with this post, it is a powerful plugin that combines functionality that was once spread across nearly a half dozen plugins.
I would encourage every WordPress using that is running their own installation to look at getting it.
Update: I checked the output from this feed after I published the post and it caused an error with the feed, removing all paragraph breaks in the post itself. I’m going to contact the creator of the plugin and see if this is a problem he is aware of.