Besides the so-so results (and the random porn images they were getting: http://www.reddit.com/comments/6tzpv/quantum_porn_cuil_reinvents_web_search_nsfw/), I have a couple additional gripes.
First, if you are entering your search and it happens to find similar keywords/phrases it will pop up the suggestion box. This is very similar to google....however once this box pops up you can no longer press the enter key to perform your search. The suggestions list steals focus and doesn't know what the tab or enter keys mean, so you have to actually click the search button.
The "Explore by Category" area is also pretty useless. Though I find it funny that a search for sql injection brought back the following category results:
- Security Exploits
- Computer Network Security
- Computer Security Organizations
- Windows Web Browsers (eh?)
- Computer Security Specialists
TRWTF is that expanding the Windows Web Browsers category lists K-Meleon, Safari, Internet Explorer (twice) but no firefox.