Me? I’m firmly in the Ulysses camp, at the moment, but that’s just me.
Excellent review of options, here. I recall an early version of Scrivener that I looked at, but the story-boarding process seemed too complicated.
Recently, I’ve shifted process a little, preferring the handy little world processor Ulysses instead of Apple’s utilitarian and all-around nice-guy word-processor, Pages.
Prior to this it was an app called ByWord, which I still own and, nope, haven’t used since finally switching over to Ulysses.