Originally Posted by RareBird
Sounds a lot more flexible than ADE and versatile.
Sure, but if you're someone like myself who purchases all their books from Kobo, then the ability to read the books on my PC is limited to ADE or the Kobo desktop aplication. Calibre cannot view books with DRM (Digital Rights Management).
I also borrow some library books. Calibre is not able to help there, ADE is required to borrow and read the book on the PC.
Given the above, I choose ADE and the Kobo application, although Caibre is nice if you have a bunch of files you like to manage, or if you have a lot of DRM free books.