I'd say there aren't nearly as many small places to find, but there are more big places to find with more stuff going on in them. The sheer number of places to find is less, but the amount of stuff to find and do is similar or more. I feel like NV has more actual stuff to do while FO3 has more places to find, if that makes sense.
Yeah I like the locations and stuff too but what I have a hate/love thing for is fixed level enemies.
Once you reach a higher level then it gives you no reason to go back to earlier points in the map and explore since the enemies are of no challenge and the loot isn't good.
So by lvl 30 the game becomes very cornered and the only places which might post a challenge is west of Vegas and the north-east part of the map.
On the other hand I love that it makes more sense with enemies now.
In FO3 when you reached lvl 20 there were little to no molerats and mostly yao guais.
It didn't make sense for some enemies to suddenly become extinct and replaced with a higher leveled enemy.
So I like that it's realistic.
But I hate that the game becomes such a cake-walk with exploration at higher levels.
So that's the beef I got with it.