I'd love to know what knobs are turned at those companies to alter results, it's something of a trade secret I guess.

Just to see for myself, I picked a search that should churn up a guy that they might find irritating and did 10 seconds of anecdotal research.

Search was 'vox day blog'.

Google, Yandex, Startpage return his blog as the first entry (perhaps after an ad). Goduckgo it was the sixth entry. Bing, it never showed up. I got bored after the first dozen pages.

What exactly does this prove? Not being a web/seach engine guy I don't know.

What I'd like to find is a search engine for which I could build a great big list of curated sites with zero results from others. I tend to look up the same things a lot and after a year or two of additions it might be a really nice thing to have.