I would not mind if 65% of the game is about Vaults. The geo-political implications! We have people who are all dressed up nice . But they are enclosed in a labyrinth of vault corridors. I am raging with emotion right now! I feel alone.
But on topic: How detailed are the Vaults? There is more than 1 or two I hope. How long will we spend time in the Vaults? Will we see a good chunk of the greater society unwilling to leave the Vaults yet still have the 3/4 outside enjoying Mojave ?'
Again, will our Main quest deviate at any point to let us enjoy Vaults and the wonders within them? If I am correct, and such things are hidden in the Mojave Wasteland, this may be the best game ever.