Sure tags work, but there is something very satisfying about clean, well-ordered directory structure that I can't shake. I'm with Syd's Mom on this - I'd like to have multiple libraries as well -- and it would be very handy if Calbre didn't delete the files as the only means to get them out of the library.
Sadly, I've had to resort to a "main collection-working library" setup whereby all my titles are held in a central directory structure and the stuff I want to read then gets copied over to the working library folder (directory) where it gets picked up by Calibre and then by my Kindle.
I like Calibre and I think it adds quite a lot of functionality to the eBook environment, and it's hard to criticise something you get for free, but (sorry Calibre) if I find a similar program that has many of the same features as Calibre and also provides folders and non-destructive removals -- I'd probably have to jump.
-- frank
|