Intrigued by all the press, I decided to check out Cuil (pronounced "cool"), which is the latest upstart trying to compete with that 800 pound gorilla in the search industry. Adding spice to the storyline is the fact that one founder, Anna Patterson, was previously a senior employee at Google.
Considering the hype, I must say that Cuil is the most disappointing search engine I have ever used. While the user interface does have merits, the results themselves are awful. I can't imagine that any self-respecting search expert would allow such a product to be released. I can only conclude that either Cuil did not have any such experts or their experts were overruled by a clearly misguided leadership.
Having read the flimsy arguments contained in the news articles, I was already skeptical even before trying Cuil. One can't hope to make a convincing argument by treating Google's search model as simply some kind of PageRank (this is almost certainly false anyways). Nor do I care that Cuil has over 120 billion pages indexed (this number is pretty much meaningless -- don't forget about the index size war from 2005).
Check out the results for "superstring theory" (first found via Digg). As of today, the top-middle image of the results page is a breast with a string tied to its nipple (probably not appropriate for safe-search). I have the results screen captured in case Cuil decides to do the smart thing and shut down their site.
I think that pretty much sums it up. Not Cuil.