A lot of where this topic has gone just reminds me of why I feel the entire hobby is trying way too hard to tell stories and has really lost sight of how best to use games as a story medium.
Id honestly go as far as the no doubt controversial statement that all of this Story Now stuff is on the same level of any given GM railroading his party in terms of how it uses games as a story medium.
Because in both cases, it puts the telling of a specific story at the forefront of the game, with everything else being secondary, at best. Whether its a prewritten story or something created ad hoc, it doesn't really matter, because its all story telling at the end of the day.
Comparatively, games as a medium for stories excel over other forms in a very specific way, in that only they can give the audience the first hand experience of the events in a given narrative. This necessarily means that gameplay, fundamentally, will always consist of a, if not realistic, then at least verisimiliar, amount of things that would never work in any other medium, but can make for an extraordinarily compelling experience in a game.
When Tony Stark builds a suit in a cave, only the rare few would find it interesting to watch the many weeks it must have taken. But if that same idea was instead gamified, and delivered through some compelling gameplay design? Thats a different story, to turn a phrase.
We'll have much of that 'boring' downtime and slow pacing that would never work well in a movie, and would need some very specific narrative riders to work in a book (see the vast descriptions of Tolkien that hinge on the slow pace of travel), but in a game, serve as very necessary breaks in what would be, in this example, highly engaging gameplay.
And what we'd get is the same broad idea, smart guy builds a power suit in a cave with a box of scraps. But what the Audience takes from it is much different. In a movie or comic book, we just see Iron Man as a crafty and resourceful character.
In a game, we are Iron Man, and we built that suit, in a cave, with a box of scraps, and the story we would tell of that experience, is where the really good stuff is. When I tell how I finally left the cave, I'm not thinking about fictional positioning or how best to hit a climax.
I'm thinking about frantically trying to get that damn suit to power up before me and my friend get shot by terrorists. I'm thinking about how my friend had the bright idea to pick up a gun and charge down the terrorists, and how incredibly tragic it was that he died before I could get to him. And I'm also thinking about how much I roasted my friend for doing something that obviously stupid so early in the game.
So in short, my point is games are at their best as vehicles for story when the game is an experience, and the story is what we remember of it. Games ought to be about story making, not just merely telling them. And getting back to what I said earlier, I feel the hobby gets lost when it tries too hard to tell stories, as story telling doesn't allow much room for story making, and thats why I'd say the two ways mentioned aren't all that different, particularly in the context of their respective games.