You are talking about an add-on? You should try to go to its support site.

Interesting. I was not aware of this feature: What happened to Tracking Protection?. Apparently that has been available since Firefox 35 and is quite effective at improving page load times.

Google News search (past month): firefox "tracking protection"

I don't know how the built-in feature compares with the extension, but the second comment below this blog post suggests that extensions may stop the requests from being made before the Tracking Protection feature would see them, so the extension would be doing the heavy lifting: http://monica-at-mozilla.blogspot.com/2015/03/how-do-i-turn-on-tracking-protection.html

You might prefer to keep using the extension. I'm not sure whether new Disconnect sites are getting added to the list used by Firefox.

For now i going to use disconnect with the privacy protection of firefox only with the Firefox developer version, delaying to the next release or when i find more info from the disconnect developers.

FYI, the app must be doing something. I just added it and almost immediately got a threat. I'm not as knowledgeable most people so I got spooked and closed that page as fast as I could. It took "leave page" box 3 times before it would close but I didn't remove the app. Guess I will see what happens.