Just wondering if the end-game is really as anti-climactic as it appeared. click the first spoiler button.

Yep, that's it, there's literally nothing else to do end-game, and restarting has so few side-quests unrelated to factions that it'll have you running over the same exact quests with very similar dialogue choices again. A mistake in the design if you ask me, even though the game itself was amazing for a first run, it lacks replay-ability of a traditional open world game.

Well there's always overseeing your settlements, collecting more of those yummy Mutfruits, making gory chunks out of Raiders/Ghouls/Super Mutants, modding your gear, and scrounging more caps and ammo, but yeah. That's about all there is until you start a new game and do it all over again.

QFT.

Everything is the same. There are a few side quests. But replaying them (like the Cabot line) are exactly the same. So yes, the replay ability of this game is very limited.