Maybe its just me but when I last tried DDG I found it to be awfully slow compared to Google and Bing.
I love DDG, and tried it out as my default search engine for about a month, but just got tired of how slow it was compared to Google and switched back to Google as my default (on DDG I found myself adding "!google" about 30% of the time anyway). If DDG was faster, I'd probably still be using it.