Tag and search through 400,000+ files
Replace Extensis Portfolio standalone and its INVALUABLE ability to monitor and instantly (10 secs)indicate upon launch where changes had occurred in the folders that were synchronized as well as create Custom Fields to hold lists of keywords in. and replace WhereIsIt and prior to that ADCatalog to identify location of all other PC files user creates. A quest for many folk out there let down by both softwares beign dropped.
Versioning, to associate the final display version of each image with the original from camera or elsewhere. Without versioning I would go back to my old folder based system which did everything else that I need quite adequately. (Honestly for me the labelling is net/net a huge waste of time, but I can't resist it whenever I'm adding new files to the database.)
Categories and tagging and then searching on the tags.