I write most of my Hubs over a period of time, saving the unfinished work on my computer. Adding to them, reworking what I wrote, proofreading, researching and adding additional information. Sometimes even removing sections that I feel are not contributing to the understanding of the article.
Then when I feel it's ready, I upload the text into individual text capsules, add images where appropriate, and play around with the formatting to make it easy on the eye, so to speak.
I think what you were asking, though, is if we upload and save on HubPages before publishing. I used to upload and publish in one session. But lately, when I'm finished as I explained above, I upload and still leave it sit before publishing. That way I give it one last go-over before I pull the trigger.
It turns out that every time I proofread I end up modifying something. So I'm never in a rush to just write and publish.