checking off every box kind of defeats the purpose - it would be the same as running the search in regular mode off the browsing collections page. what DS does is allow you to restrict the search to only a few fields.
for a classic example, let's say you want to search roman As coins. since the word as would appear nearly everywhere in different parts of a record it would be very difficult to isolate just the asses out of the rest of the coins. so running a search of as with just the denomination field checked should return only good, focused hits. different combinations of fields can be used. for example, we could look for all asses of severus alexander and caracalla and so on.
of course, this in large part depends on how the users code in their records. in the above scenario you can upload 1000 caracalla asses and not get a single hit if the denomination field was left blank.
this is the beauty - and bane - of having so many fields to work with. on the one hand it allows for very precise database management, organization and research but on the other it only realizes its potential if the fields are coded in the first place.