Rated 5 out of 5 stars

The add-on does exactly what it says it'll do--nothing more, nothing less. I was pleasantly surprised with my experience using Facebook without the ads. For the sake of product testing, I opened Facebook on a separate web browser without any type of ad-blocking software installed. This add-on legitimately makes a difference when it comes to the user experience. The Facebook UX is made far more enjoyable (specifically, no more targeted ads).
It's fairly easy to use, as there is no restart required. I changed the current BubbleChat messenger interface to the old style Chat interface, which I missed, and there were no differences in terms of Facebook Chat's functionality. The add-on's description says you can change the font of the Facebook page but I wasn't able to access this feature. It ultimately didn't make a difference because it's not something I needed, and I'm sure that if I had spent more time with the add-on (which I will) I'll be able to figure it out.
Overall, I had a fulfilling experience with the app.