An irritation for me with DDG is them formatting result URLs incorrectly, and then ignoring any feedback about it. Two examples are them adding spurious www. prefixes to Google code results, and leaving out slashes when creating Apple developer URLs.
DDG could distinguish themselves by playing bazaar to Google's cathedral, but they don't appear to. A search engine that uses crowd sourcing and feedback would be disruptive IMO.
The examples. https://duckduckgo.com/?q=apsw - note the second link is on google hosting and shows code.google.com/p/apsw/ but clicking on it gives page not found because it goes to WWW.code.google.com/p/apsw/. https://duckduckgo.com/?q=NSString and note infobox at top which goes to Apple developer but clicking gives an error. The link should have a slash between Reference and NSString at the end.