For what it's worth, on Dreamwidth since the posting limit is so much bigger you could probably do many fewer separate entries to get the whole fic in. So if that's a factor to consider...

And I second the comment above about AO3, I really love that readers can choose to list the whole fic on one page if they wish and the author can also choose to have chapters, and they work for both people.

Personally I like one page because I often knit while I'm reading, and it's a lot easier to just hit a key to page down than to click a link for the next chapter, while I'm holding knitting needles and yarn and all that.