I actually find the atmosphere alot better in FNV. Ive just entered freeside, and man. The place isnt big but I love it.
One thing that I actually have found funnier is that in FNV, you are a pretty regular guy. You dont have a father that tries to save the whole land, youre just a guy that have happend to get the wrong mission in the wrong place.
In FO3 you were the center of the world, three dog talked about you whatever you did. I just feel alot moore immersed in vegas then FO3. And in my point of view, atmosphere isnt dungoun crawling and shooting monsters.
But hey, im a swede, my country hasnt been in war for the latest 200 years