For everyone saying you have to play one way and you cant choose how you want to go, I don't agree. You cant "lose" the game unless you die, so really, you have options.
But anyway...
At first I was a little sad to see there was no Karma, but now that I've played a lot, I can see the Karma has been replaced by companions. There are certain companions you need to do nice things with, and certain companions you need to do bad things with. I think its a great system. Like in order to get Strong's affinity perk, you have to do things that certain other companions wouldn't like.
I don't know, I just think its a brilliant game. I'm sure the patches will improve the framerate drops