This is very clearly an improvement on Fallout 1 in seemingly every way, from how there is so much more to explore to how leveling up skills like lockpick and science has a lot more use. The story also while less lonely and hopeless has more interesting twists, with a genuinely terrifying antagonist.
But I can't help but feel it's also a good example on why bigger is not always better. Mechanics which were only slightly annoying in 1 become a real pain here, such as map encounters being extremely hard half the time.