There are numerous books in the standard collections that I will never use (e.g. all of the Syriac and Aramaic stuff). Some books from earlier versions of collections have been superseded with later versions of the book (e.g. NA26 has been replace with NA 27 Greek New Testament). I want to be able to delete what I have no need for. Just like I sometimes go through my physical library and give away or thrown out things I no longer need, I ought to be able to do this with my digital library.
I like that Logos 3 lets you choose what books you want on the hard disk (so does Bible Works and many other programs). I would like this capability back in version 4. An option to delete a book from the hard disk would be great. Perhaps when a books is hidden it should be removed from the disk at the same time.
My laptop space is precious. I had to remove a year's worth of digital photos to make room for Logos 4. I want to regain some of that space and remove clutter in my library.