When clicking on project/node -> "Search History" there is a query form (based on SVN example) and, by default, all fields are empty. 

I think that the "From:" field should default to few days, maybe one-two weeks in the past. Leaving that field empty and pressing 'search' on large and old repository results in a very very long waiting (like several minutes).

Providing a few-days-ago date (even two weeks) results in almost instant response and this is what usually everyone wants. 

Next step could be to separate this field from revision and entering a calendar component, but that is really not that easy as just providing a default date.