Great add-on slowely falling appart Rated 1 out of 5 stars
Perfectly merges the URL and search bar, while maintaining sufficient privacy by allowing the search suggestions only to come up when the engine's keyword is typed. Due to lack of maintenance it has however been falling apart with code syntax in the URL presentation, a browser freezing link to the old search engine management and broken switching to open tabs as of Firefox 47.
Solid alternative Rated 5 out of 5 stars
It's one of the few merged URL-search bars that easily allows me to only restrict search suggestions to when I first type in a search engine keyword, which I think is crucial for a privacy focused browser.
Meanwhile, as the previous review has noted, there are some irregular internal suggestions as of Firefox 43. In addition I also can't bring up the "Manage Search Engines" menu from the search engine list without locking up the browser interface, probably because Mozilla has replaced that with the in-browser "about:preferences#search" version.