While there is flexibility in screenplay formatting (what to highlight in an action line, for example), if you deviate too far from the norm, you're going to raise questions about your competency.

It would be the same if you asked people to read your novel and disregarded punctuation and grammar...

If you arbitrarily break the rules, you will distract others from looking at your content, which seems to have happened.

I think the BEST argument for using standard formatting is because when you use it correctly, it disappears.

And that's what you want.

You DON'T want the reader to notice your deviations from format or your inability to create proper margins.

You DO want them to notice your great script.

For an experienced reader, asking them to read a script that's formatted incorrectly is absolute torture, because the differences cannot be ignored.

So if you put something out there to be read, and it deviates from standard format, it's automatically pissing a lot of people off, and it makes it SO much more difficult -- in some cases, impossible -- to fairly judge the content.

Personally, after using Final Draft, going back to using Word for student scripts is quite an experience. Final Draft disappears into the background and allows you to just write.

I just want to say "Yep" to everything Susan wrote.

I used Word on the first screenplay or two that I wrote and found it completely unwieldy. Plus it was really difficult getting the margins right and no matter how many times I proofread, there was always an extra goof that stayed hidden until I printed it.

Using World to write a screenplay is like cutting down a tree with an hand saw as opposed to a chainsaw. Yeah, it can be done, but you'll make a lot more work for yourself.

The main thing that makes a dedicated screenwriting program important for me is that I don't have to think about formatting. Slug lines are already in caps. Dialogue is already indented. I don't have to waste time typing each character's name over and over when they speak and I also don't have to worry about misspelling a character's name like with a typo (unless it's in an action line). Margins are set, there's no weird page breaks like right after a slug. Continued's can be automatic. And when all this happens, I can focus on the story I'm telling rather than the page layout. I don't even need to spend laborious hours re-formatting after it's written.

I understand about the cost and if someone already owns Word, why waste money. But if one is serious about pursuing a vocation, even as a hobby, use the right tools. If you want to be a surgeon, sure you could use a steak knife--it cuts--but a scalpel will do the job to the best outcome.

I believe it is important to stick to screenplay format (especially since I've had it hammered into me in every screenwriting class I've taken). As a reader it drives me nuts when people do strange things with format. It's confusing. It detracts from what you're actually saying.
On the other hand, when I'm asking someone for feedback, I HATE it when people comment on typos, formatting issues, etc. I know I made mistakes. It's a draft. It's not a finished script. I want to know if the story, characters, etc are working before I go back and correct every little last detail.

That said, I use Celtx and it works great for me, but I usually write everything out longhand (scenes) or in Word (outlines) before typing/pasting it into Celtx and formatting. Writing by hand keeps me focused on my story. I find my computer too distracting (email, IMs, Google, Wiki are waaaay too tempting).

Use Word and you have to spend more time to formatting than actual story.

I started with Word once and also had the idea that formatting was no big issue.

It becomes a big issue when you use a program not suited for movie scrips.

With Final Draft, I don't have to worry, just write.

I actually have heard people complain that screenwriting programs were too confining. I never got it, but it it's getting in the way of pounding out a rough draft, fine, go ahead and write that in Word. Then put it into your screenwriting program. Or maybe do a few drafts in Word. Then put it in a screenwriting program. Later drafts are less about bursts of creativity. More about correcting specific issues.

I also wouldn't say that things like em-dashes are formatting issues. Those are style issues. That stuff will vary based on the tone you're going for. If your action script has a bunch of dashes, and your suspense movie has a bunch of vertical writing, and it's to get across your tone, I don't think that has anything to do with "hardline formatting."

And please don't take offense, I can understand complaining that everyone corrected formatting issues, but I'm sure a lot of people think that if you (generically, the writer) don't have the time to proof things, then why should I (the reader) waste my time reading it?

There's an old John August article where he talks about this. Professional Writing and the Rise of the Amateur Specifically the Presentation, a.k.a. “Giving a shit” section.

I'm selling two copies of FD7 for cheap.

I think that "proper" by the books formatting is essential to know, like all the "rules" of screenwriting. How you present your story is as important as what you say, the story you tell, the characters you create.

The format is the interface with the reader. If you don't know how to format in a way that makes the reading transparent, you will set up a massive barrier between you and your reader.

Having said that, if you know the rules, then you should creatively break them. That's what will make your script and story unique.

Look at Walter Hill
Look at Wall-E.
Look at Shane Black scripts. And Quentin too.

They all knowingly break the rules. The key is to do it knowingly.

Having said that, if you're a genius, then you can format your script any way you want. You just better be amazing!