I do have a local instance of etherpad but the friction to get it running seems to be just enough to prevent me from firing it up. So mostly I use either textmate or something called writeroom. I like using textmate with markdown because you can highlight something, hit ⌘I, and it's italicized.

For a while I thought where I wrote mattered, but after producing good and bad just about everywhere I decided to just go with whatever jumps to mind first.

I'm amused when I look back at my "breadcrumbs," but I don't know if they're useful. They're just a record of a struggle you already went through. So it's not like you're going to learn a whole lot of new stuff.

Where they're useful is when you think to yourself, "maybe the way I phrased it was better." I did that a number of times, and probably wouldn't have been able to if I hadn't used etherpad.

It's really tough to say. I bet a lot of the benefits would accrue over the long run.