Eh. The Dragon Age games use map nodes, and it's kind of dull. I mean, 10 years ago, sure, they had to use map nodes if they wanted a world the size of Fallout 1 or 2, but nowadays there's no excuse for not actually putting some detail into the world.
So.... no. Map nodes in a modern game just reeks of lazy developers.
As seen in both Fallout: New Vegas and Fallout 3 one big map can only hold one real town and even that town has to be scaled down.
Fallout games used to be about the towns and cities, not the random wasteland.
So a map node system is > than a big sandbox map for Fallout games.
Besides, they could use 8 maps that are somewhat bigger than Point Lookout that include some exploration along with the realistically sized settlements, towns and cities.
And outside of these maps there could be tons of hidden locations on the world map which we can only find out about from talking to NPC's or we could have greater chance to find them on our own depending on how high our Survival(Outdoorsman) skill is.
All these maps could have that detail.
And it's not lazy to use map node system, it's done to give the world of the game a greater scope, to show how big it is and that places have realistic distance between each other.