For simple queries 'strncmp', 'giraffe', 'sound transit schedule' ... Google, Bing and Samuru perform pretty well. But Samuru is extremely slow.
For more complex queries like, 'seattle dumpling restaurant that is famous in singapore' or 'how to zip a list in ruby'. I find that Google always comes out on top, bing lacks the previous search history to personalize my searches and often thinks I mean (zip as in zipfile)... But samuru gave me relevant results for all three which is rather surprising.
Another type is one for people/social related searches... Bing's facebook/twitter/linkedin/yelp integration actually makes it better than google because the 'snapshot' bar it has is super helpful. However Samuru results are on par with Google and Bing results here (minus the snapshot bar).
Overall I was skeptical but other than it being unbearable slow (Google spoilt us with speed), Samuru does have very good search results for what I assume is not a mutlibillion dollar product.