@
fidvo - most operating/file systems have pretty sophisticated search. If I needed to find a book with 'Night' in the title and I didn't have calibre running, or it was running against the wrong library, I would use my file manager to do a Find file, it would find the 36 books I have with 'Night' in the title in a couple of seconds.
But say I want to find all 'books' whose text contains the words 'CoCo Bond' or 'Contingent Convertible Bond'. I can find the 84 of 90+K books in my three libraries in a couple of seconds with my desktop search tool - plus the 4 emails in which they're mentioned. In Calibre I only have the QC plugin search, it would take a month of Sundays to do the search, it would only search in epubs (11 of the 84 'books' are PDFs that are 'too hard' to convert) - and it would never find the emails.
I can even add a Windows Saved Search as a book. When I 'View' an MS-SEARCH, Windows executes the search, so the results will include freshly added books, and it will take about 1-2 seconds because Windows has already indexed the content.
For me it's not a choice of using calibre OR file system based tools. I use calibre AND file system based tools, and with the Import List and especially the Drop Search Results plug-ins I can 'integrate' the two.
If I couldn't make use of non calibre tools against the data in my libraries I wouldn't be using calibre. The only constraint calibre imposes is that I don't use file system tools to add, remove, move, or rename folders and files in its libraries. I can live that
BR