I spent a hell of a lot more time on chapter 1 than the others. i basically played the game like this
-Prologue. Nice start, sets the scene well. Enjoying it.
-Chapter 1. WOW! this is amazing. I could explore this place forever. What a game!!
-Chapter 2(Roche's path for first playthrough). OK, still enjoying it, a bit of a letdown but i'm sure it will pick up again in the next chapter when we get to the next town

- Chapter 3. Ok there's not much to explore here, or many NPC's to talk to. I wonder when i will reach the next town?
- The word epilogue flashes on teh screen. WTF

Is that it?
As i said, i did enjoy the game, but overall i have to say i was slightly disappointed with it. A rating of 8/10 seems about right for it tbh.