Just a heads up for Nightly users: browser.urlbar.speculativeConnect.enabled

[publicarray]

Nightly users concerned with privacy probably want to turn this off: browser.urlbar.speculativeConnect.enabled

It is designed to improve performance by starting a connection to an autocompleted hostname from the awesomebar. e.g. type fb and Firefox makes an autocompletion to facebook.com and may start connecting to facebook.

https://bugzilla.mozilla.org/show_bug.cgi?id=1348275

https://hg.mozilla.org/integration/autoland/rev/071beab1c31e

[earthlng]

https://bugzilla.mozilla.org/show_bug.cgi?id=1355443#c10

browser.search.suggest.enabled is the general pref that controls suggestions in both the location bar AND the search bar.
browser.urlbar.suggest.searches is a sub-pref that controls the behavior only in the location bar.
Additionally, keyword.enabled is a pref that controls whether the default action from the location bar should be a search.