Oh, I'm not saying that NV is a masterpiece, far from it.
Like you said, since they can't change the gameplay substancially, they at least provided good quests and some very inspired dialogs.
For example, I was reading how the perks would be implemented in Van Buren and it seems that perks would be tied to player characteristics and skills, rather than player's level.
Now, what a friggin' good idea.
Say I'm a courier who likes to when possible resolve problems by talking and his build is constructed around explosives/melee.
I play on PC, so I don't neeed VATS, since my mouse is accurate enough for targeting. So i reach level 18. In FNV I have available Computer Whiz, Concentrated Fire, Infiltrator and Paralyzing Palm.
What possibly use my build have for this? Or even luck, since explosives don't have critical hit and melee have low critical damage, so better criticals is more or less useless to me.
Usually we ended picking some perk for earlier levels, but wouldn't be nice to have perks focused on my characteristics, rather than on my level?
Also, NV world gives too much for the player, you only suffer shortage of edibles, chems, stims and so on if you want or are in the first playthrough.
Things should be earned, not given.