A. Ease Of Use: 3.5/5 – Fairly easy to setup (But fairly difficult to understand what this add-on actually does). Just select what you want blocked. By checking off the box or boxes you want and your good to go.
B. Security: 4.5/5 - Ideally this add-on can pretty much cover all the Internet browsing protection you will need. (If setup correctly and paired with NoScript)
C. Usefulness: 5/5 – Ghostery sees the “invisible” web, detecting trackers, web bugs, pixels, and beacons placed on web pages by Facebook, Google Analytics, and over 600 other ad networks, behavioral data providers, web publishers – all companies interested in your activity.
D. FireFox Slowdown: Depends on the web page. But generally there is some mild to heavy lag (But will vary based on computer and Internet connection)
E. Computer Slow Down: No lag that I noticed. But FireFox does seem to use more memory faster. When Ghostery is active and in use.
F. Type Of User I Would Recommend To Use This Add-on: A more advanced Firefox user would find this add-on way more useful. Then a novice no doubt about that.
Till The Next Review,