It would be nice to have a "Blank" option for fields in the Data slicer so you could do a query for "Is blank" or "Is not blank".
Here's an example of why this would be nice: I was trying to come up with a list of students who had withdrawn, which is basically anyone who doesn't have an Exit Status. The only way to do it was to add an "Exit reason is..." OR statement for each exit reason (Exit reason is Financial or Exit reason is Personal OR.... you get the idea)
It would be much easier to just say "Exit reason is Blank". :-)
