Cuil is utterly useless
Is not a search engine. It does not crawl the web. it does not return links.
It is an interface to some useful databases, and it is very useful if used appropriately. I use to occasionally. If you expected it to be a search engine, it is not surprising that you have been disappointed - just as someone who buys a sports car for carrying cargo will be disappointed.
I have not found it to be much better than Yahoo. It is an improvement over the old Live Search, and is much better presented and marketed. So far my audience do not seem to use it (I rank better than in Google and get hardly any traffic from them).
Competition is search is good, but it could hardly come from a worse source.