One thing that I immediately notice when I tried out Ask was that it is constantly suggesting search terms as I am typing my request. This helps very quickly to narrow one's search. I think it would be especially beneficial for students who don't tend to type in any more than one term or two at the most or for anyone who has difficulty thinking of search terms. Ask also offers to expand or narrow my search at each step. I got helpful results as I searched terms pulled from Sun Signs like astrology, horoscopes, etc. However, on a personal note I checked out tickets to Stomp performances in Las Vegas and got many results that had nothing to do with Stomp but only to Las Vegas. Checking out the help section tells me you can use questions, natural English, word strings, etc. to search. It mustn't use the same search logic as Google to provide results.
KartOO made me feel old!! The sprinkly lights zooming around to highlight my search on the web were very distracting. I was very overwhelmed by my results when I tried the same search terms as I did for Sun Signs above. However, searching a topic I had used in grade three, burrowing owls, did bring up several of the sites I had found previously and used. I think it would be interesting to watch students play around with KartOO and see how they search with it. I didn't feel it was my "style".
I realize what a rut I've been in always using Google as my seach engine. Is it worth the effort to learn another one? Hmm.....