I used DDG for a few weeks and I'm glad I did because I'd forgotten just how good Google is. A few things that DDG made clear was: 1) How useful personalized search actually is. I like that my search engine knows what city I live in so when Googling the name of a restaurant I don't have to include it (that I don't live in an American city might emphasize this). 2) How much speed and responsiveness matter in web design (not to mention autocomplete). Searching google is a much, much smoother experience.

DDG is really good at returning a good result for a really general search term like "C++". However, for me at least, that is an extreme edge case.