I tried 5 searches about subjects I knew well. Results: Google 4, Yahoo 1, Bing 0. But in every case I had to look closely at the results to decide which I preferred. None of them returned obviously bad results for any of the queries.
This application is weird in cases where spell correction comes in to place. Just search for mike tieson, birack obam, pal graham hacker news and you can see the difference between google results & what's shown on the blindsearch application. There's a whole lot of difference.
I searched for Patti Blogovich (intentionally misspelled). All three columns contained what appeared to be relevant results, but after reading the returned articles, only two articles were outstanding (on depth and "objectivity"). One of these was halfway down the column for what turned out to be Google. The other was the top result for Yahoo.
Then I searched for "wriggly wrolly," which I sometimes call my dog. I ended up clicking for Yahoo again, which had all 4 results.
Sure, only two tries, but I was really surprised with how rewarding this experience was. I wish I could use Yahoo but have it look like Google. I'm just so hooked on Google's branding and image, rather than my 90's-based judgments of Yahoo...maybe I can be stronger of that and make the switch...maybe.