I never do partials - WAY too much stress. I'd get messages every day asking when the next chapter was coming, especially if I had something come up and was delayed at all. As it is, I get daily requests for a Z9 review and setup guide, as well as requests to update the AF book. If I were to sell an incomplete item, I'd spend all my time answering e-mails about when the next part was coming instead of working on the guide, complete with a reminder that they had already paid for it
AlsoI do understand how anxious people are and I will do my best to get things done as quickly as possible. However, I also won't shortcut things. I think the reason people like what I do is because I don't base everything off of a couple days at a local park. I really test and try and my ideas in the field and you only hear about them once I have a solid, field-tested setup ready.