DDG is my default search engine, I do find myself needing to occasionally throw in !g if I'm not finding what I'm looking for. Results are generally decent though, and the trend seems to be that they are getting better and better (though I have not objectively measured that in any way). The other ! shortcuts are worth reviewing, as they can dramatically improve the results if you're doing a focused search.

So true. One of the nice things about the !bang syntax is that it's pretty intuitive. Although one can accomplish something similar in the browser via smart keywords, the DDG way lets anyone jump right on to any machine and focus a search on a particular site. By picking the first letter or a two letter combination, e.g. !hn=hackernews, I don't have to look up the exact !bang for a site.