This is something I often consider when writing; should I leave the draft at a pivotal story moment, or at the chapter’s end. There is no straight answer, but I think it is great to do both – in other words, have one’s cake, and eat it too! But on a more serious note, it has more to do with the writer, and what they are writing – that is, the story itself.
If you find that leaving the story at a section makes you salivate to write the next instalment then this is good; it shows that the story is having an effect on you as a writer, which can make the story all the more delicious to write! On the other hand, if you find it is easier to complete the chapter, and this leaves you hanging, and anticipating to write the rest of the story, why not. It’s whatever we are comfortable with, can manage, and find stimulating in the writing process.
It also depends upon the story, and what we wish to convey through it to the reader. I am currently in this process with a mystery-romance story I’ve been working on, and I have found that leaving the story at a main point is making me want to finish it when I can, as the suspense is exciting during the writing. As a backup with everything, it is always helpful to have a breakdown of events, the ‘bare bones’ of the story that you can refer to whenever necessary, to keep you on track when completing the project.
It doesn’t mean, though, that everything has to be cut and dry; changes always occur when writing, ideas and concepts crop up that didn’t previously enter the mind, and these spur you on to write, and make the story the best it can be. And, of course, finding those ‘ah’ moments that leave you excited, and aiming to finish your manuscript!