It would a nice little improvement if the Properties Dialog for the GDB also provided the total file size of the GDB. Currently, in order to get filesize information at the GDB level, you have to go to the Parent Folder where the GDB resides and if you haven't already, alter the ArcCatalog properties to display the 'Size' when you are in Detail View.
It would be much more convenient to be able to just get that information from the properties dialog like so: