When I first started playing I thought it was pretty demanding. Going from GTA4 where people will die in a headshot, to people who will take several blows to the head seemed a little odd.
However once I got into the game it was pretty awesome. Even after you complete all the quests there's still a lot of material to find. Like an alien blaster, or a room filled with blood and plungers, or even talking power armor.
Plus the DLCs are pretty cool looking so far. Still waiting for a level cap increase.