I agree with Sonneilon about the DVD breakdown concept. I have small children, so I usually have to watch DVD's or longer dios in multiple viewings. It's not ideal, but it is what it is. Also, the Seinfeld psychological concept of "leaving on a high note" or leaving the fans "wanting more" is a valuable tool. This also drives us back over and over to the site to see if there is an update. So I would say chapters/parts are the way to go.
(But what do I know, I've only been contributing photos...)
Seriously, I admire all of your work, and I find myself visiting on a daily basis. I have ideas in my mind of what I'd like to do, but time is not at a surplus right now.
Take care, and I look forward to new dios in the future!