The proofreaders, editor and I put a great deal of work into the stories that I post on SOL. I think those stories deserve a chance to find a readership. The best way to let readers find the story is to post it as a serial.
I take a sort of between route. I write the story as a single novel and it's complete before I start to post it. Then I post it in what I call SOL Parts, segments of between 5,000 to 10,000 words with a number of complete chapters or sub-chapters in each Part. That gets the best of both worlds, in my mind.
As to my editors, one prefers to have the whole story to work on at once and does it all in one go, the other prefers to get it at once and to work on a few chapters at a time, but setting his own pace. Even so, he gets the full story back to me within a few weeks.
However, whatever method you use, it has to be one you're comfortable with. I have one, you have another, and others have different again. Whichever method you use you need to be aware of how that it can have an affect on the story development and take that into account. But, best of all, just keep writing.