Well, I got over 100 hours gameplay out of the main game. 35 hours for the main *story* is about right, but for TLAD I remember reading previews on several sites that said it added 35 hours of gameplay.

Of course, the new story is only 8 or 9, but I was expecting side missions and stuff to knock it up to 35. Yes, there are races and gang warfare things to increase the length, but surely not to 35 hours. Unless the 50 hidden seagulls you have to kill are stupidly difficult to find.