Personally, as long as the story's easy to read, I prefer the 'wall of text' on FA! There are some things that just don't translate well from pdf files to FA... why not both? Have the file ready to download for those who prefer it that way, and the story underneath?

Posting it in the description allows you to post alongside the art, which works well for small sequences... not necessarily what you do, though.

Mind you, some people for one reason or another can't access a reader for PDF files at all times, or a good universal document editor. For those people, some writers do their best to post stories as notepad. Stories posted with the note format also load right in the browser page, so it can be read no matter the available software on any given computer. This does put a larger burden of editing on you, but those who edit well normally produce acceptable quality stories.

Personally, SoFurry is a bit superior to stories, but that's just me. I can understand the desire to stay here, and personally check all three art sites regularly.

I usually prefer reading the stories directly on FA, but that's just me.

i say it depends on the length of the story.
If it's long, then it should be on PDF file to make it easier, cause the comment boxes don't translate well in story-telling, like you have to press the space bar multiple times to make it like a proper paragraph indentation.
If it's short then put it in the description box. I mean I sometimes write something like a short story on the fly, like with how you see some of my submissions.
but that's just me

Realistically it's best to have .pdf and wholesale in the description, since the vast majority of people read from the description.

However, I've learned that 11k words is the limit to the description box. In that case, I just add a link to a Gdoc with the story in the description instead, alongside a disclaimer saying the story was too long.