For the longest time I've written my stories in Word. It suits me, just bashing out words in a word processor, but it can be awkward when I go back to edit and I need to find a certain part, or want to move chapters and so on. I got a trial of Scrivener a few years ago and quite enjoyed it, so I decided to take the plunge and buy the full version. I'm hoping it will help me be more organised and make my editing easier.
I'll post a review in a few weeks once I've had a chance to use all the features!