There's no reward for finding them though. I didn't even know they existed until I was about 25 hours in. Worst game I've ever completed
Yes, I was very disappointed by this. The atmosphere was pretty good, the facial stuff is great, and the music is excellent.
However the game itself is just not good enough. The lack of a home base really makes it suffer for me - if you had a house, perhaps the wife could have been characterised better as you would see her every time you go home. As it was, Phelps wasn't a complex character but really a badly written one with contradictions. Some of the script was pretty awful too. Just frustrating because I think it's pretty close to being a great game.
Six months more in development focusing on the characterisation, replay value and ironing the plot would have been preferable to a game that initially excites, enthralls, and then about half way through just makes you go 'meh'.
Having said that I'm actually tempted to play through again and get the DLC extra cases...just to see if they assist the plot when you slot them in there...