Social Fixer has significantly improved my Facebook experience, allowing me to remove or hide many of Facebook's annoyances, from sections in the margins (or the margins themselves) to functions such as notification bubbles and inaccurate timestamps.
I've found the subscribed and user-created filters indispensable in removing or segregating News Feed posts, and the ability to create or add stock code snippets has fixed many issues I had with Facebook from its appearance to its functionality.
Version 22 has brought improved functionality of the Friend Tracker and now allows adjustment of the threshold at which FB Friend deactivation and reactivation events are reported.
Importantly, answers to user questions are quickly addressed by the developer (Matt Kruse) and his team via developer pages and very active subscriber groups. There is also a page for developer and subscriber provided display and functionality tweaks.
Social Fixer has made my Facebook experience tolerable and even enjoyable.