I've been interested in switching to DDG for a while but as a former Sprint customer, that statement scares me but maybe some explanation from you might understand your opinion better.
Often I do get a good result on the first page but often results #1-#N vary from third rate to non-sequitur and then result #N+1 is the one that should be at #1, where maybe N is drawn from Uniform(3,6). I see this so much I can't imagine it is an accident. If anything it seems to be 70% more evil than Google.
The real difference is non-technical things. Google filters out unflattering results and one side of anything even remotely political. It's a nerfed world, kind of like a Disney theme park. I'm an adult and I don't need to be led with blinders to the googly viewpoint.
Isn't DDG just a Bing wrapper with a few frills in the results?
I think bing is close to Google in quality. Some people might even like it better. On the other hand I think DDG is the Sprint of search engines.
Google used to have a search API and they discontinued it because they said most of the people who used it were SEO people.
People who do pay-per-click are into A/B testing and other quantitative testing. Google is all for you doing that if you pay for advertising. Their mainstay of anti-SEO is doing arbitrary and random things to make it impossible for SEOs to go at it quantitatively. (They have patents on this!)
One reason so many sites go to a harvesting business model is that once a site is established you can make the slightest change and then your search rankings plummet. If you depend on search engine traffic it is a huge risk that you can't do anything about unless you are about.com (bought a 'competitive' search engine and just might be able to make an antitrust case against Google.)