The game is completely different, Iron sights changes the game dramatically, you actually fire where you aim, and you can snipe people one shot one kill with sneak attacks across a field. Six shooters are awesome, Shotguns actually work (As long as you don't use VATS)
And I can fire now without relying on vats for everything. The combat feels so much better, Hardcore mode adds the exploration feel.
Just is better, is new, the story is completely different and better, the atmosphere isn't depressing, it is more like a wildwest adventure, humor is now a lot more prominent too.