I've decided that although I really like Scrivener as an editing tool, it would be a better editing tool if I had it on my laptop, which doesn't have the Mac OS on it and therefore can't run Scrivener. Scrivener helps me to focus in on where a manuscript is broken and work on just that part (mostly). The other thing Scrivener is good for is reformatting a manuscript quickly -- it seems more and more on-line markets are coming up with their own formatting hoops to jump through.
But tonight when I went back to using plain old Word on the laptop, I discovered that I do some of my best writing in a discovery mode. And it may help that I do my writing out of the house, where I'm less easily distracted. And, to be truthful, the laptop doesn't have an internet connection, so I can't get sucked into e-mail or research.