disable online searches under privacy
install unity tweak tool
disable search for files and more suggestions
And that is something that most people if not an overwhelming majority of Unity users are going to be doing, therefore these features shouldn't have been included in the first place.
Even then, what if you simply don't like Unity's layout and the way it looks? One could install another desktop environment, but that defeats the purpose of installing Ubuntu in the first place. That, and there are a lot of visual hiccups that come with installing DEs other than the system default.
did you install 13.10 or 12.04
With 13.10, you get slowness and unstability. With 12.04, you get outdated packages with limited functionality. It's a lose-lose, because canonical and other linux development groups that promote this "periodic release" practice are apparently allergic to updated software.