This extension is very good. I haven't noticed my computer lagging. It's interesting to see how many trackers there are on websites I previously considered to be rather safe. Definitely recommend :)

privacybadger has learnt to block two new trackers since I installed it

I've been using this extension for almost three years now, and I'm still convinced that this is the best privacy extension I've ever used!
Very clear controls. No fuss and no "unblocking" of trackers beyond my control. And although the description doesn't seem to mention it specifically, this extension also appears to block most ads.
This works for me!