Database size of powerset search engine is very less than google. So it display limited search results. Still I prefer powerset. Specially when I don’t have exact word to search.
Searching over powerset is based on natural language processing. It can understands your question and arranges the results accordingly.
I searched for “kangana”. Powerset identifies it as people name. And gave little bibliography of the person. Then it displayed the rest results. While google takes it as a word only. Google doesn’t categorized or grouped the result.

Even though I prefer google. Why?
I prefer powerset when I am not having exact word to search. I searched over powerset, collects word and prepare new search query for more relevant search through google. I never prefer powerset for recent news or images or any activities. As per my opinion, powerset is very good search engine but for historical search only.
I feel powerset is just a very good replacement of wikipedia. If you are preparing reports or working on some case study then powerset can help you a lot.
What I missed in powerset…
Safe search off
There is no option to enable or disable safe search. Although the contents provided by powerset are filtered in itself.
Real time search
Powerset doesn’t search for current activities or news. It just searched over wikipedia.
Less data base size
Large database provide you better results. It also helps to bring most popular and relevant web pages in front of users. Even though powerset give most relevant search. Still the contents provided them are not sufficient to me.
Why powerset is best?
If you consider powerset and google as two people and whole world as library then I would say that powerset will bring you only the books you really required. On the other hand, google will bring many books which may or may not suite to your searches.
Why google is best?
Powerset searches over limited data. So the results are not rich enough. If you are searching for basic principal then one good book may be sufficient for you. But if you are searching for tips & tricks or some smarter ways to do the same task then you’ll have to refer other books and research papers as well. Google has huge amount of data. So it gives more result. Some of them may suggest you some different and better result which you might not expected. Moreover google scans all web periodically. So the contents provided by google are generally latest.
When to use powerset?
As I already had written above, If you are not having exact word what you are searching for, then you must prefer powerset. Moreover if you are doing some case study or preparing reports then powerset can help you a lot. Besides, google search for words in a statement but powerset can understand a question. So if you are writing a question like “Where is mumbai?”, then powerset can give you more relevant results.
Please note this
There is no comparison between google and powerset. It depends on what you are searching for.