I thought the ending was incredibly disappointing (I chose to save Arcadia Bay). From the moment they introduced the whole 'travel through photos' thing, everyone knew the devs would end up using it for the finale. As soon as the game started to introduce alternate timelines it was obvious that the choices you've made would be rendered pointless. I was hoping that it would be a Chapter 4 exclusive thing but obviously this was not the case. Near the end of the game where you've got the choice the save people, why would you bother wasting your time? You know that (as far as the story goes) this timeline isn't the one you care about, so why bother caring about saving anyone there?
I understand the whole idea of "it's about the journey, not the destination" but I feel like the ending could have been done a little better than that.
I saved everyone because I didn't know if things would play out perfectly with the photos and had no idea where I'd end up. Might as well help where I can along the way. I couldn't imagine trudging through seeing everyone dying and then have the game be like "haha it didn't happen" or something.