My personal criteria is “likelihood of being finished” regardless of how long it is. Part of what I like about book 1 being a separate PDF is that no matter how long it is till the next part is done, you have one section that you can point to and say “finished.”
I also try to judge by that, although its not always easy to do so. I also like the idea of Book 1 being separate, for many of the other reasons you gave.
My personal criteria is “likelihood of being finished” regardless of how long it is. Part of what I like about book 1 being a separate PDF is that no matter how long it is till the next part is done, you have one section that you can point to and say “finished.”
I also try to judge by that, although its not always easy to do so. I also like the idea of Book 1 being separate, for many of the other reasons you gave.