Greetings!
I have been having mixed thoughts about giving a single download for everything, the different "editions" are essentially the same book with different code listings, where you can choose your favorite programming language and just download the edition you need.
I have also thought of offering a single download (containing both PDF and EPub versions) for each "edition" (thus cutting the number of available downloads in half), as an effort of simplifying the file list.
Maybe after some changes that are going on (like the "single download for all formats" i mentioned above), I may add a "The complete collection" download that allows to download everything at once, for the sake of user-friendliness.
Thank you for your suggestion!