As for the "something else" gain, my concern with this is that it is only claimed, not observed. You don't know what DDG does with your data, you have their word for it. You might think that they don't use your data because you don't see personalized results, but what people forget is that DDG is not a search engine in itself but rather a wrapper around other search engines: Bing, and the Russian search engine Yandex. At least Bing does not provide personalized search results as-a-service.