I watched exactly half of Gerry but I decided to turn it off after watching a close-up shot of their faces as they walked for literally 5 straight minutes.
The director (Gus Van Sant) made a few recognizable movies like Good Will Hunting and Milk, but Gerry reminds me a lot of Elephant, another movie he directed about a school shooting. Both movies involve incredibly emotional sitautions, but yet the characters in the movies have almost no personality or emotion. In Gerry, they never seemed to care that they were lost and without water. There was one scene in which they were camping for the first night of being lost, and instead of panicking over being lost in the desert like most people would, Affleck went on a 5 minute spiel about some strategy video game. Personally, I don't see what the advantage to this style of directing is since I end up not caring about the characters.
On a side note, I also found the scene where Affleck was on the rock to be almost infuriating. First, if he got up there in the first place, he could've gotten down. Second, it would've been a four foot fall if he just sat on the edge of the rock and dropped, let alone if he hanged by his arms. Instead he actually did a vertical jump off the thing. Finally, I don't really want to watch Matt Damon collect dirt for 20 minutes.