I think it’s safe to say that DuckDuckGo is not quite as good as Google when it comes to search. But it’s not bad at all.
But it’s a lot cleverer than Google. It’s almost as though, rather than working on cloning Facebook, making creepy glasses, or trying to beat Apple by acquihiring a bunch of ex-Apple guys they’ve actually been trying to make a better search engine. To begin with, if you set DDG as your default search engine (on Safari this actually means installing an extension, since Apple doesn’t let you add it the obvious way) your address bar becomes a command line, with special (and very convenient) commands.
For example, if you want to use Google, you simply prefix your search with !g. So there’s that. If you want to use Bing, you can use !b, and !i for Google Image search. If you want to search for something on Amazon it’s !a. Stackoverflow !so. That’s actually enough — right now, DDG wins. Here’s a link to all the bang commands.
Now of course the main argument for DuckDuckGo is that it makes its money comparatively honestly by selling search terms without tracking its users. Well, it claims not to track its users, but even if it does it’s probably advantageous to not have your email, searches, and ad-clicks all being tracked by one entity, right? At least make them work for a living.