Just here to bump this and say that I just discovered this feature by accident searching for a Spanish song by typing "y me voy" (without quotes) so it searched "me voy" in yahoo instead of google, problem is, I usually go to youtube writing "y" and then pressing enter, now youtube is the second option and can't delete "y/" from suggestions, for a single feature that didn't know that existed for years, that'll ruin my experience for the rest of my time using this browser.
So please, allow users to both customize and disable the feature, as it is not a bad thing itself, what is the problem is that you can't either customize it or disable it, and it IS a problem, if it's not clear with this amount of people randomly discovering this and being a problem for them.