It's worth finishing just for the story RW. Masterpiece of game storytelling in my opinion. So much depth to all the characters, the game is at its best when you're going slow and taking everything in, not when you're stuck completing questionably railroaded missions in a very specific way. Only complaint is that the disconnect between the organic and open natured game world, and the blinkered story missions can sometimes break the immersion.
Just started another game and I just use it to unwind and relax, go on a hunting trip and stuff.